Subsections

Food poisoning


Algal Toxins

Algae

Algae may present variable morphology. Species are known being unicellular, other algae may grow up to 20 to 30 meters of length.
Algae serve as food for marine animals, they may be used as ingredients such as the production of agar agar, used in food, in drugs, as basis for bacteriological medias and is used in many other ways. Chlorophyll is often hidden by yellow, brown,blue and red pigments.This gave the origin to a classification of algae in Xantophyceae, Cyanophyceae or Rodophyceae.
Algae produce starch, mannite, leucosine and oil.
Algae are generally inhabitants of water. Algae adapted to life in contact with air are found on the surface of rocks, on the bark of trees and at soil. In extreme cases they may survive at 70$^{0}$C (Cyanophyceae).
Algae are an important factor of regeneration of water and treatment of drinking water. Microscopical identification of algae is used in the characterisation of quality of water.
Algae are important part of marine plankton serving as food for a variety of aquatic animals. Chlorella pyrenoidosa, unicellular alga was studied as a possible food. Rodoficeae are industrially used to obtain natural carotene. In reduce amount dehydrated algae are used as food in Japan.


Classification of alga

[92] Classifications are often not up to date but some are didactical and will still be used even when there is a new classification proposed so this is why the present classification proposed by Strasburger is used here: The plant kingdom is divided in 7 great divisions :
  1. Bacteriophyta containing bacteria
  2. Cyanophyta containing the blue-green Alga
  3. Phycophyta containing all other alga
  4. Mycophyta containing mushrooms
  5. Bryophyta containing the mosses
  6. Pteridophyta containing ferns
  7. Spermatophyta containing plants with seeds
Alga which produce toxins are settled in division 2 Cyanophyta and division 3 Phycophyta.

Division 2: Cianophyta:

The division contains the following orders:

Division 3: Phycophyta:

This division contains algae organised as Flagellatae with the following orders: The Flagellatae have subdivision

Classification of microorganism according Streble

[96]
  1. Phylum Bacteriophyta(Bacteriae) Order Eubacteriales
    Order Actinomycetales
    Order Chlamydobacteriales
  2. Phylum Cyanophyta(Blue algae) Order Chroococcales
    Order Pleurocapsales
    Order Chamaesiphonales
    Order Stigonematales
  3. Order Chrysophyta(Yellow algae) Class Chrysophyceae(Gold algae)
    Order Chrysomonadales
    Order Rhizochrysidales
    Order Chrysocapsales
    Class Bacillariophyceae, Diatomae ( Diatom )
    Order Centrales
    Order Pennales
    Class Xanthophyceae (Yellow-green algae)
    Order Heterogloeales (Heterocapsales)
    Order Heterococcales
    Order Heterosiphonales
  4. Euglenophyta Order Euglenales
    Order Peranematales
  5. Phylum Dinophyta Class Dinophyceae
    Order Peridiniales
  6. Phylum Cryptophyta
  7. Phylum Chlorophyta(Green Algae) Class Chlorophyceae
    Order Volvocales
    Order Tetrasporales
    Order Chlorococcales
    Order Ulotrichales
    Order Ulvales
    Order Prasiolales
    Order Microsporales
    Order Chaetophorales
    Class Oedogoniophyceae
    Class Bryopsidophyceae
    Order Cladophorales
    ivermectin Order Sphaeropleales
    Class Conjugatophyceae
    Order Mesotaeniales
    Order Gonatozygales
    Order Desmidiales
    Order Zygnemales
  8. Phylum Rhodophyta(Red algae) Order Banglales
    Order Nemalionales
    Order Cryptonemiales
  9. Phaeophita(Brown algae) Order Ectocarpales
  10. MycophytaOrder Archimycetes Order Phycomycetes
    Order Ascomycetes
    Order Basidiomycetes
    Order Fungi imperfecti

Algal toxins

Beside useful algae there are many single cell algae which produce toxins. These species develop rapidly under favourable conditions forming algae carpets in seawater killing fish in Mexico gulf and North Sea (such as Microcystis).
Marine animals such as oysters,Crustaceae and different types of fish may eat the toxic algae storing the toxins. This can lead to serious poisoning.
According to the species of algae the symptoms of poisoning are[89]:
  1. Damage of the nervous system (Paralytical Shellfish Poisoning)(PSP)
  2. Loss of memory(Amnesic Shellfish Poisoning)(ASP)
  3. Neurotoxic phenomenons(Neurotoxic Shellfish Poisoning)
  4. Sodium channel blocking in nervous cells(Tetrodotoxin)(TTX)
In the summer the temperature of seawater rises causing high growth of algae. In the Netherlands the harvest of oysters are stopped at this time of the year or the oysters are transfered to unpolluted water tanks to regenerate.

The alga Fibrocapsa japonica was found in the German Bay. This alga produces a toxin which is associated with the death of seals. According to Ursula Siebert from the Forschung und Technologie Zentrum , Büsum, Germany, was found in samples of the German Bay for the first time in 1995. How the toxin of Fibrocapsa japonica acts and if it can harm humans is unknown[511]. In USA and Canada the maximum tolerable value of saxitoxin is 0,8 mg/Kg of mollusc meat. In Germany absence of liposoluble DSP is provided by regulations. Water soluble PSP should not exceed 400 micrograms/Kg of mollusc meat. The maximum tolerable amount of dominoic acid in Germany is 20 mg DA/kg mollusc meat.


Harmful Algal Blooms (HAB):

Harmful Algal Blooms (HAB) is a natural disaster which has attracted global attention in recent decades since it threatens greatly public health, causes economic damage to fisheries and tourism. Fibrocapsa japonica is one of HAB causative organisms which caused significant loss to coastal fisheries in Japan. From the 1990's it was also reported frequently in European coastal waters.

In a work of the University of Oldenburg, the toxicity of Fibrocapsa japonica algal cells was first established by Artemia salina biotest. Fibrocapsins was screened step by step through Artemia salina biotest, bioluminescence inhibition biotest and erythrocyte lysis assay methods, isolated then in HPLC.

The chemical natures of fibrocapsins 1, 2 and 3 were determined finally as 6,9,12,15-octadecatetraenoic acid, all-cis-5,8,11,14,17-eicosapentaenoic acid and all-cis-5,8,11,14-eicosatetraenoic acid by HPLC-MS, IR, GC-(HR)MS, NMR experiments and biotest. The toxins are unsaturated fatty acids. (Isolation and characterisation of toxins from Fibrocapsa japonica (Raphidophyceae) / Meng Fu. - 2003. - V, 85 Bl. - Oldenburg, Univ., Diss., 2003)

Harmful algae blooms buoy: Dr. Phil Culverhouse from the University of Plymouth developed the HAB (harmful algae blooms)-Buoy. This project was funded by the European Union. The buoy is a swimming microscope coupled natural object recognition software. It can image and recognise harmful algae. It will be operated either underwater suspended from a buoy or on a mussel-producing raft, or in the laboratory to monitor algae. The relevant specimens which are scanned from filtered water will be further analysed to decide on their species label. This enables shell fishery staff to have advance warning that HAB species are present. Tests are instruments will be located in Galicia in Spain, Galway in Ireland, and the Gulf of Trieste in Italy.


Damage of the nervous system (Paralytical Shellfish Poisoning)(PSP)

They are caused by toxins produced by Dinoflagelata such as Alexandrium spp. The PSP toxins are water soluble.

Analytical methods

Mouse-Bioassay: A biological test giving immediate informations about the activity of the toxins in whole. To study the different paralytic toxins chromatography methods are necessary, such as the use of the ionicpair chromatography with RP-C18 and a step gradient making possible to separate PRP toxins.


Damage of the digestive tract (Diarrhetic Shellfish Poisoning)(DSP):

Toxins of Diarrhetic Shellfish Poisoning (DSP) are okada acid (okadaic acid) the Dinophysis toxin, the pectenotoxins and yessotoxin which are liposoluble causing strong diarrhoea.

Analytical methods

At the beginning there were only biological tests in rats and mice, the Bioassays and immunological tests, the immunoassays. Modern HPLC methods with derivatization before column with fluorescence marker using a fluorescence detector can detect very small amounts of toxins.
Using HPLC/MS coupling with Atmospheric Pressure/Electrospray Ionisation (API/ESI)-Interfaces better results may be achieved.


Loss of memory (Amnesic Shellfish Poisoning)(ASP)

A poisoning with ASP in Canada affecting about 100 persons was related in 1987. These persons had eaten meat of mollusks which were intoxicate with ASP. The survivals had amnesia. This gave the name of the poisoning which is caused by the dominoinic acid of the alga Nitzschia pungens. This alga is found also in Europe turning oysters poisonous. The maximum tolerable amount of dominoic acid in Germany is 20 mg DA /Kg mollusc meat.

Analytical methods

HPLC is used as analytical method of ASP using an RP-C18 column without derivatization. Dominoinic acid down to 1,0 mg/kg mollusc meat can be detected with this method. Making derivatization of dominoinic acid before the column using fluorenilmetoxicarbonylchlorid. Amounts below 1 mg/Kg can be detected.

Neurotoxic phenomenons(Neurotoxic Shellfish Poisoning):

The NSP toxins are produced by Gymnodinium breve, also denominated as Ptychodiscus brevis.
This alga has several times caused death to fish in the Gulf of Mexico.
APS toxins may be classified in to types: Brevetoxin A and Brevetoxin B. They are a group of polyethers.

Analytical methods:

HPLC and immunoassays and HPLC with MS coupling.


Sodium channel blocking in nervous cells (Tetrodotoxin)(TTX)

Tetrodotoxin is also called fugu-toxin. It may be produced by some fish of the family of Tetradontidae (Takifugu sp.). This ball-fish is being consumed in Japan causing sometimes severe poisoning.
The toxin TTX blocks the sodium channel of nervous cells acting neurotoxic.
This toxin has no absorbtion of ultra violet light and is not fluorescent.
HPLC is used with derivatization before column, producing a fluorescent derivate with sodium hydroxide.
The HPLC/MS coupling with an API/ESI interface is used with good results and in some cases chromatography with mass spectrometry recheck.

Saxitoxin:

Saxitoxin is an algal toxin of the PSP type, being water soluble. More 20 derivates of saxitoxin are produced by Dinoflagelata such as Alexandrium spp.

Analytical method to determine Saxitoxin [78]

Summary:Saxitoxin is an algal toxin which is extracted in acid solution.
After extraction the toxin is purified with periodic acid in alkaline medium. Saxitoxin is then read fluorimetricaly against a standard curve.
The food to be analysed is triturated in trichloracid 1 N and hydrochloric acid 0,2N in equal parts.
After 20 minutes heating it is filtered, taken to pH 5.2 +-0.1 with potassium hydroxide 1 mol/l and centrifugated and transfered to a column with ion exchange resin in ME+ form 50 to 100 mesh to purify the saxitoxin.
The column is then washed with 100 ml buffer of potassium acetate at a pH of 5.2+-0.1 followed with 50 ml distilled water.
Saxitoxin is then eluated with sulfuric acid 0,5N until 20 ml are obtained in a volumetric flask.
The velocity of elution should not exceed 3 ml/minute.
2 ml of the elution are mixed with 2 ml NH$_{4}$OH 1,2 N and 100 microliter of periodic acid 0.1 ml/l. After 15 Minutes 200 microliter of glacial acetic acid are added to the solution and read against a blank containing the same components as before having periodic acid changed with water.
Standard solution: Saxitoxin dissolved in acetic acid 0,1 ml/l. Further dilution are made with sulfuric acid in a way that 2 ml of the dilutions are added to 2 ml NH$_{4}$OH 1,2 N and 100 microliter of periodic acid. Reading is made at 388 nm. The blank should be subtracted from the value of the sample. Before using purifying column the resins must be suspended three times in 50 ml chloridric acid 3N and washed with distilled water until reaction is neutral.
Again the resin must be suspended 2 times in 50 ml acetic acid 2mol/l. The upper layer is then exchanged by 150 to 200 ml acetic acid and the pH is adjusted to 5.2+-0.1 with acetic acid. The resin can be kept until use under a buffer solution of potassium acetate 0,2 mol/l at an pH of 5.2+-0.1 adjusted with acetic acid. The column of 1 cm diameter is charged with approximately 5 g resin which gives a length of 5 cm.

Health regulations related to bivalve molluscs and other marine species

[79]
Health concerns related to shellfish, live bivalve molluscs and other aquatic animals contaminated with coli, salmonella or other bacteria or viruses as well as algal toxins are of public concern. Actual global warming may spur micro organisms in water turning and turn it necessary to tighten safety control on molluscs.

The Council Directive 91/492/EEC of 15 July 1991 lays down the health conditions for the production and the placing on the market of live bivalve molluscs. It define production areas from which molluscs can bet gathered for direct human consumption, or from which they have to be purified or relayed.

It is primarily the responsibility of the producers to ensure that the bivalve molluscs are produced and placed on the market in compliance with the health requirements prescribed; whereas the competent authorities must, carry out checks and inspections, to ensure that producers comply with those requirements do not contain microorganisms and toxic substances in quantities which are considered to be dangerous to human health.

Live bivalve molluscs from purification areas must not exceed the limits of a five-tube, three-dilution MPN-test of 6 000 faecal coliforms per 100 g of flesh or 4 600 E. Coli per 100 g of flesh in 90% of samples.

Live bivalve molluscs from areas where they do not exceed the limits of a five-tube, three-dilution MPN-test of 60 000 faecal coliforms per 100 g of flesh.can be collected but placed on the market only after relaying over a long period (at least two months).

Requirements concerning live Bivalve Molluscs intended for immediate consumption

1. The possession of visual characteristics associated with freshness and viability, including shells free of dirt, an adequate response to percussion, and normal amounts of intravalvular liquid.

2. They must contain less than 300 faecal coliforms or less than 230 E. Coli per 100 g of mollusc flesh and intravalvular liquid based on a five-tube, three-dilution MPN-test or any other bacteriological procedure shown to be of equivalent accuracy.

3. They must not contain salmonella in 25 g of mollusc flesh.

4. They must not contain toxic or objectionable compounds occurring naturally or added to the environment such as those listed in the Annex to Directive 79/923/EEC. [80]

5. The upper limits as regards the radionuclide contents must not exceed the limits for foodstuffs as laid down by the Community.

6. The total Paralytic Shellfish Poison (PSP) content in the edible parts of molluscs (the whole body or any part edible separately) must not exceed 80 microgrammes per 100 g of mollusc flesh in accordance with the biological testing method - in association if necessary with a chemical method for detection of Saxitoxin - or any other method recognized in accordance with the procedure laid down in Article 12 of this Directive.

If the results are challenged, the reference method shall be the biological method.

7. The customary biological testing methods must not give a positive result to the presence of Diarrhetic Shellfish Poison (DSP) in the edible parts of molluscs (the whole body or any part edible separately).

8. In the absence of routine virus testing procedures and the establishment of virological standards, health checks must be based on faecal bacteria counts.

Algal toxins, new detection methodes

[81]
Algal toxins may be present in shellfish, molluscs and other marine and fresh water inhabitants. Global warming may spur algal blooms which highlights the importance of algal toxins detection.

Maximum levels and Detection methods are described in the Decision 2002/225 EEC.
(1) Chapter V, point 7, of the Annex to Directive 91/ 492/EEC provides that the customary biological testing methods must not give a positive result to the presence of diarrhetic shellfish poisoning (DSP)in the edible parts of molluscs(the whole body or any part edible separately).

(2) It has been scientifically proven that certain marine biotoxins such as those of the diarrhetic shellfish poisoning (DSP)complex (okadaic acid (OA)and dinophysistoxins (DTXs)) and also yessotoxins (YTXs), pectenotoxins (PTXs)and azaspiracids (AZAs), pose a serious hazard to human health when present above certain limits in bivalve molluscs, echinoderms, tunicates or marine gastropods.

(3) In the light of recent scientific studies it is now possible to establish maximum levels and methods of analysis for those biotoxins.

This Decision lays down the maximum levels for the marine biotoxins of the diarrhetic shellfish poisoning (DSP)complex (okadaic acid and dinophysistoxins), yessotoxins, pectenotoxins and azaspiracids and the methods of analysis to be used for their detection. It applies to bivalve molluscs, echinoderms, tunicates and marine gastropods that are intended for immediate human consumption or for further processing before consumption.

Maximum levels  
   
Okadaic acid, dinophysistoxins  
and pectenotoxins together 160 μg of okadaic acid equiv./kg.
   
Yessotoxins 1 mg of yessotoxin equivalent/kg.
Azaspiracids 160 μg of azaspiracid equivalents/kg.

The EU EFSA Panel recommends reduction of EU Okadaic-toxin limit

[82]
Okadaic acid (OA) and its analogues, the dinophysis toxins (DTX1, DTX2, and DTX3), together form the group of OA-toxins. These toxins are lipophilic and heat stable, are produced by dinoflagellates and can be found in various species of shellfish, mainly in filter-feeding bivalve molluscs such as oysters, mussels, scallops, and clams.

OA-group toxins cause Diarrhoeic Shellfish Poisoning (DSP), which is characterized by symptoms such as diarrhoea, nausea, vomiting and abdominal pain. These symptoms may occur in humans shortly after consumption of contaminated bivalve molluscs such as mussels, scallops, oysters or clams. Inhibition of serine/threoninephosphoprotein phosphatases is assumed to constitute the mode of action of OA-group toxins.

According to the Panel OA appears to be not mutagenic per se, but induces changes at the chromosome level and is aneugenic in vitro. The Panel noted that these effects may be related to cytotoxicity of OA.

The Panel concluded that a lowest-observed-adverse-effect-level (LOAEL) for human illness is in the region of 50 microgram OA equivalents/person, this approximates to 0.8 microgram OA equivalents/kg bodyweight (b.w.) for adults. An uncertainty factor of three was applied to extrapolate this LOAEL to a no-observed-adverse-effect-level (NOAEL) which resulted in an ARfD of 0.3 microgram OA equivalents/kg b.w.

Based on data provided by five Member States, the Panel identified 400 g of shellfish meat as the high portion size to be used in the acute risk assessment of marine biotoxins.

It was noted that a 400 g portion of shellfish meat containing OA-group toxins at the current EU limit of 160 microgram OA equivalents/kg shellfish meat would result in a dietary exposure of 64 microgram toxin. For a 60 kg adult this is equivalent to approximately 1 microgram/kg b.w. This figure exceeds the ARfD by approximately 3-fold. The Panel concluded that in order for a 60 kg adult to not exceed the ARfD, a 400 g portion of shellfish should not contain more than 18 microgram toxin, i.e. 45 microgram OA equivalents/kg shellfish meat.

The mouse and the rat bioassay are the officially prescribed reference methods in the EU for the detection of OA-group toxins. The Panel called for a validation of the phosphoprotein-phosphatase assays and liquid chromatograph-mass spectrometry (LC-MS) to replace actual methods.

Detection methods

Detection methods are described in the Decision 2002/225 EEC. Biological methods: Use mice or rats. The tests involve the death of the animals.

Alternative detection methods:

A series of methods such as high performance liquid chromatography (HPLC)with fluorimetric detection, liquid chromatography (LC)-mass spectrometry (MS), inmunoassays and functional assays such as the phosphatase inhibition assay can be used as alternative or complementary methods to the biological testing methods, provided that either alone or combined they can detect at least the following analogues, that they are not less effective than the biological methods and that their implementation provides an equivalent level of public health protection:

- okadaic acid and dinophysistoxins: an hydrolysis step may be required in order to detect the presence of DTX3, - pectenotoxins: PTX1 and PTX2, - yessotoxins: YTX, 45 OH YTX, homo YTX, and 45 OH homo YTX, - azaspiracids: AZA1, AZA2 and AZA3.

On market available kits for the detection of algal toxins

Saxitoxin (STX) is a neurotoxin found in marine dinoflagellates (algae). It is a selective sodium channel blocker. It is so strong that it is known as "TZ" chemical weapon by the U.S. military with the Lct$_{50}$ of 5 mg . min/m$^{3}$. [83] The medical importance is in relation to red tide in shellfisch because of the paralytical shellfish poisoning (PSP) food poisoning. The blocking of the sodium channel produces a flaccid paralysis that leaves its victim calm and conscious through the progression. Death is caused by respiratory failure. [83]

A Saxitoxin (PSP) algal toxin immunoassay ELISA kit is now commercially available among others: The Direct ELISA Enzyme Linked Immunosorbent Assay (ELISA) has proved to be a sensitive and rapid method for phycotoxin detection, such as:

Yessotoxin (YTX):

Yessotoxin and its analogues produced by marine algae, in particular Protoceratium reticulatum and Gonyaulax polyedra. YTX is known to accumulate in shellfish meat and is regarded as hepatotoxic and cardiotoxic when ingested above a certain level. The yessotoxins have previously been included in the diarrhetic shellfish poison (DSP) group, but the YTX chemistry and toxicology differ distinctly from the DSP toxin family. The European Commision recently placed the yessotoxins in a separate phycotoxin group, and implemented a maximum permitted level (MPL) of 1 mg YTX eqvivalents/kg shellfish intended for human consumption (Directive 2002/225/EC). [84]

Microcystins / nodularins and its congeners detection kit:

It responds to a broad range of the toxic microcystin congeners, as well as the structurally related nodularin toxins.The ELISA is derived from antibodies recognizing 6E-ADDA,the common structural feature present in the toxic congeners of microcystins and nodularins. [85]

Dominoic acid:

The amnesic shellfish poison (ASP) toxins, domoic acid (DA) and DA isomers are water-soluble neurotoxins produced by a number of marine algae, in particular by the microalgae of the genus Pseudo-nitzschia. Blooms of Pseudo-nitzschia spp. may lead to the accumulation of DA in shellfish filter feeders and other marine species. Ingestion of DA contaminated shellfish may lead to amnesic shellfish poisoning (ASP) by affecting the central nervous system, and has caused the death of both animal and human consumers in severe cases. The European Commission Directive 2002/226/EC implemented a maximum permitted level (MPL) of 20 mg DA/kg shellfish intended for human consumption. This MPL is adopted by the regulatory authorities in most other countries. This quantitative DA EIA kit detects DA in water samples shellfish and algal extracts The assay is primarily intended for use in routine monitoring of DA levels in bivalve molluscs to comply with the regulatory MPL, but is also applicable for DA quantification in the marine matrixes. [86]

Cylindrospermopsin:

It is a naturally produced toxin of several cyanobacterial strains and has been found in fresh water throughout the world. Certain strains of Cylindrospermopsis raciborskii (Australia, Hungary, United States), Umezakia natans (Japan), Aphanizomenon ovalisporum (Australia, Israel) have been found to produce cylindrospermopsin.

The production of cylindrospermopsin seems to be strain specific and not species specific. The antibody binds Cylindrospermopsin The assay sensitivity allows the determination of Cylindrospermopsin in a range of environmental samples (water, fish tissue, fish plasma, etc.). [87]

Microcystine ELISA Test:

Microcystins and the structurally related nodularins are toxins produced by cyanobacteria (blue-green algae). Acute poisoning in humans and animals can be caused by these toxins and in several cases has led to death. These toxins inhibit liver function and might act as tumor promoters. Many different structural variants (congeners) are found, with the most common variant being microcystin-LR. To protect public health, the WHO has proposed a provisional upper limit for microcystin-LR of 1 ppb in drinking water. [88]

Bacterial poisoning

Bacteria can settle on food. Due to industrialisation and globalization they can be widespread turning: The bacteria present in food can:


Examples of microorganism which spoil food:

Molds, yeasts, Escherichia coli, Proteus etc.


Examples of microorganism producing toxins:

The microorganism cited below can produce toxins when present in food and having sufficient time during storage under appropriate temperatures. In this case the microorganisms don't necessarily need to be alive when reaching the final consumer.:
Laboratory diagnosis: Sometimes the microorganism which spoiled the food are dead because the food was sterilised after deterioration. In this case chemical analysis may bring the evidence of undesired microbiological activity, such as the rise of ergosterol or rise of acidity in salads or succinic acid in egg yolk.

Bacillus cereus produces endotoxin about which there is little known. Bacillus cereus produces hemolysin and lecithinase which is not toxic and is a phospholypase.

Campilobacter jejuni produces endo- and enterotoxin.

Clostridium botulinum produces exotoxins from type A, B, C, D, E and F.
They are the strongest toxins which are known and act as neurotoxins. They inhibit the excretion of acetylcholine avoiding thus the transmission of signals from the nerve to the muscle causing paralysis comparable to the effect of curare, the poison of South American Indians.
The endotoxins which are thermo unstable are formed in canned food with a pH higher than 4.5 and about 6 month of storage.
This toxin is destroyed when food is cooked before serving.

Clostridium perfringens produces an enterotoxin formed in bad refrigerated precooked food.

Escherichia coli produces an enterotoxin under bad hygienic conditions.

Listeria monocytogenes produces listeriolysine.

Salmonella enteritides produces a heat unstable exotoxin mainly in ground meat, in eggs, in poultry, in milk powder, in chocolate and fine salads.
Salmonella typhimurium produces a heat unstable exotoxin.

Shigella dysenteriae and Shigella sonnei produce endotoxin or heat unstable exotoxins.
Shigella dysenteriae, Shigella sonnei and Staphylococcus aureus, produce thermostable toxins.

The toxins produced by Staphylococcus aureus can be classified serologically as toxin A, B, C1, C2, D, E and F.
About 19% of Staphylococcus aureus are toxin producing strains.
The toxin A and B are resistant to very high temperatures and may resist even to 20 minutes at 121,1$^{0}$C . Often there are no sensory changes in food with staphylocoxin.

In the production of industrialised food all efforts should be made to avoid a contamination of food with Staphylococcus aureus, paying great attention to avoid handling of food by person with suppurative focuses.
Streptococcus faecalis, produces thermostable toxins
Vibrio cholerae produce enterotoxin.
Vibrio parahaemolyticus produces exotoxin.
Yersinia enterocolytica produces enterotoxin.


Examples of microorganism causing infections

:
All microorganism cited as producer of toxins of the above paragraph are able to cause infections. The microorganism must be alive and in sufficient number to cause an infection.


Staphylococcus aureus penicillin resistant

Staphylococcus aureus has experienced increasing resistance to antibiotics. The first reports from penicillin-resistant isolate, type 80/81, came from Australia and Canada in 1953, causing skin lesions, sepsis and pneumonia in children and young. The hospital and community acquired infections were treated in the 1960s with meticillin


Community-acquired MRSA (ca-MRSA)

Emerging infections with community-acquired MRSA (Ca-MRSA) picked up in public places is resistant to meticillin antibiotic. It is believed that the strain of Staphylococcus aureus may have evolved from the 80/81. Key regions in genes of community-acquired MRSA are identical to the genes of the 80/81 strain. It is therefore believed that the cMRSA strain has developed from this strain through several intermediate steps. The total genetic code differs from the hospital form.

One important toxin of cMRSA Staphylococcus aureus is Panton-Valentin-Leukozidin (PAL), responsible for the necrosis of wounds, abscesses and pustules and is determined by the gene lucks-Luke.

The Ca-MRS strain was described in USA and Canada in 1994. The germ has a specific gene "lucks-Luke" which produces a necrotic toxin causing deep necrotic wounds. These wounds must be surgically drained. Sometimes amputations becomes necessary.

German, French and Swiss samples of cMRSA are resistant to fusidin acid. This indicates the formation of a new strain of Staphylococcus aureus. Intercontinental spreading of the cMRSA is demonstrated by the finding of the MLST- Type STr with the element SCCmec type IVa in USA as well in Germany. [1500][1501]

There are nasal carriers which may spread the bacteria causing what is called a skin and soft tissue infection SSTI. Contamination occurs during body contact, smears by hand contact, crowded living conditions. Insufficient personnel hygiene.

Avoiding cMRSA: Strict personnel hygiene, Hexachlorophene Hexachlorophene should be used for hand disinfection. Avoiding crowded living conditions. Football and wrestling being a sport with body contact should take precautions on these matters.[1502]
An undersupply of vitamin complex B due to a food insufficiency or single-sided nutrition may lower immunity regarding pustules. Yeast extract or food supplement of complex B vitamines may be useful to body's defence, and may in some cases even avoid infection.

Examples of microorganism which can act as opportunists:

Candida albicans can cause infections of mouth and digestive tract by persons with weak immunological system. Yeasts being found in food should be controlled in regard of the presence of Candida albicans.


Mycotoxins

Mycotoxins are poisonous metabolites of certain moulds which can cause pathological changes in human and animals. The most important species which produce mycotoxins are Aspergillus, Penicillium and Fusarium.
Intoxication takes place through ingestion of contaminated food more seldom by inhalation or skin resorption.
Mycotoxins unlike the bacterial or algal toxins generally do not produce acute intoxication but they are known as strong carcinogenic, teratogenic with chronic activity.


Contamination with mycotoxins

Direct contamination with mycotoxins can take place when moulds grow on the food.
Indirect contamination can take place mycotoxins contaminated feed is ingested by cattle and pork. Milk, eggs and meat are examples of indirect contamination of food caused by spoiled feed containing Aflatoxins Ochratoxin A and some of the Fusaria toxins.
The direct contamination caused by on food growing moulds is of great importance on cereals, oil seeds, coffee, fruits, vegetables, spices some types of cheese like Roquefort cheese and meat products.


Aflatoxins

Aflatoxins are mycotoxins which are exclusively produced by the mould Aspergillus flavus and Aspergillus parasiticus. Of importance are the aflatoxins B$_{1}$, G$_{1}$ and G$_{1}$.

Aflatoxin B$_{1}$

Aflatoxin B$_{1}$ is the strongest carcinogenic compound known. It causes liver cancer. In food aflatoxin M$_{1}$ is sometimes present and is almost as poisoning as aflatoxin B$_{1}$

\includegraphics[width=450bp, height=200bp, angle=0]{library/Aflatox.eps}
In animal feed the most frequent aflatoxin is B$_{1}$ being often found together with Aflatoxin B$_{2}$, G$_{1}$ G$_{2}$


Ochratoxins


Fumonisins


Trichothecens


Zearalenon


Citrinin


Patulin

Fusaria toxins

[494] Fusaria toxins is a generic term for the so called fade-toxin produced by Fusaria moulds which produce wrinkling of plant parts.
Moulds which produce fusaria toxins are:
Fusaria sporotrichiella
Fusarium tricinctum Fusaria diverisporum Gibberella zeae There are not enough official data related to fumonisin available in order to define limits of fusaria toxins in food. There is currently no official limit for fumosins in food, however,the EU has proposed a limit of 500 microgrammes per kilogram [495].The following results of tests are published:

Maize flour, polenta, maize semolina:
290 samples were analysed with following results:
58% below 30 $mu$g/Kg
23% from 30 to 500 $mu$g/Kg
17% $>$500$mu$g/Kg
The highest result was 9818 $mu$g/Kg. The group of maize products has therefore the highest concentration of fusaria toxins of all food on test.

Fumonisin was found over all in Italian maize and over 1000 $mu$g/Kg in biological maize cultures.

Extruded products, Breakfast cereals:
The content of fumonisin of these products is much lower as found in maize:
About 25% below 30 $mu$g/Kg
74 % from 30 to 500 $mu$g/Kg
1% $>$ 500 $mu$g/Kg up to 1600 $mu$g/Kg
Sweet corn:
Fumonisin content found in sweet corn was very low.
More than 85% had not detectable amounts of fumonisin.
5% from 100 to 500 $mu$g/Kg
Baby food. From 149 samples only 2 samples were positive to fumonisin with a maximum concentration of 55 $mu$g/Kg.
According to the German Institute of Consumer Health Protection and Veterinary Medicine (Bundesinstitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin BgVV in Berlin the contamination of cereals with Fusaria is increasing resulting in higher content of fusaria toxins in baby Food containing cereals.
The Fusaria moulds grow on the cereal stalk and transfer their toxin to the grain. The most important of these toxins are desoxynivalenol (DON)also known as vomitoxinVomitoxin), and fumonisin. They damage cells und interfere in the immune system. In wheat and maze products there were found up to 600$mu$g/kg food.

Desoxynivalenol may coexist with Zeralenone. Desoxynivalenol causes growth depression and suppression of the immune system. 1 ppm limit in the sole feeding should not be exceeded. Zearalenone may cause fertility disturbances on the oestrogen production in pigs.

Consuming one or several meals with 20 g of fusaria contaminated cereals the tolerable daily intake (TDI) of 1$mu$g will be surpassed. All effort should be made to discard batches of wheat, maize, and cereals with fusaria toxins. The control of the raw material should be intensified in order to guarantee low levels of fusaria toxins.
Wheat, beer, oil seeds and spices:
640 samples were analysed with no positive findings.

Fusarium sporotrichoides

This mould grows in the surroundings of the Baykal sea and other parts of east Siberia, in the north of China and North Korea. It grows on cereals producing toxins which cause the Kaschin-Beck-disease which is a chronic osteoarthrose which begins in early childhood resulting in heavy disorder of growth, deformation of the extremities.The toxins of Fusarium sporotrichoides contract the vascular system which serves the epiphysic cartilage and metaphysis resulting in disorder in the growth of cartilage which can be observed not only in humans but also in dogs and rats which had been fed with corn covered by Fusarium sporotrichoides.


Other Fusarium:Fusarium poae, Fusarium lateratium

, Alternaria and Cladosporium fagi can produce toxins resulting in the toxic aleukie. The moulds grow on cereals specially on millet left during the winter on fields.
The disease develops in two phases : First there is a burning feeling in mouth and throat,nausea,gastroenteritis,vomit and diarrhoea.After these signs there is a leucopenia within two month which may result in sepsis. Additionally there comes to trombopenia and aplasie of red marrow. The mortality is high.The toxins are not inactivated by cooking. There are three toxins known: Sporofusariogenin, epicladosporic acid and fagicladosporic acid .

Ochratoxin A

Ochratoxin A [496] is a mycotoxin produced by moulds of genus Penicillium and Aspergillus. It is a water soluble cumarin derivate

\includegraphics[width=350bp, height=200bp, angle=0]{library/Ochratox.eps} It is found in cereals,coffee, spices and other foods.
The growth of moulds and production of ochratoxin A is speeded by high temperatures and high moisture during:
Harvest,
handling,
drying,
storage and
transport.
The daily intake of ochratoxin A in Europe is 0,7 to 4,6 ng/Kg/day.
In Germany the daily intake of ochratoxin A is estimated 0,9 ng/Kg/day.
Sources of ochratoxin A are: Cereals with 0,5 ng/Kg, coffee with 0,2 ng/Kg and beer with 0,2 ng/Kg.
Ochratoxin A is carcinogenic and genotoxic in mice and rats.
Recommended limits of ochratoxin A are:
Cereals and their derivates maximum 3 micrograms/kg
Ingredients for baby foods maximum 0,3 micrograms Coffee green or roasted maximum 3 micrograms/kg. Mixing of different charges of coffee to reduce the content of ochratoxin A is not allowed.

Ochratoxin and aflatoxins in spices

Ochratoxin A (OTA) is a mycotoxin produced by several fungal species of the genera Penicillium and Aspergillus. Contamination of food commodities, including cereals andcereal products, pulses, coffee, beer, grape juice, dry vine fruits and wine as well as cacao products, nuts and spices, has been reported from all over the world. In addition, contamination of animal feeds with OTA may result in the presence of residues in edible offal and blood serum, whereas the OTA contamination in meat, milk and eggs is negligible. Despite efforts to reduce the amount of this mycotoxin in foods as consumed, a certain degree of contamination seems unavoidable at present.
The Expert Panel of the European Food Safety Authority reported that the dietary exposures of adult European consumers to OTA ranged from 15 to 60 ng OTA per kg bodyweight per week. Tolerable Weekly Intake (TWI) of 120 ng/kg b.w. for OTA was derived by the Panel. [497]

Spices and paprika are often contaminated by aflatoxinx and ochratoxin. Aflatoxins are the only mycotoxins with legal limits for spices in the European Union. A limit for ochratoxin A is expected to be adopted soon. Limits set up by EC No. 1881/2006 regulation are 5 µg/kg for aflatoxin B1 and 10 microgram/kg for total aflatoxins, but no legal limit for ochratoxin A exist. [523]

According to Hernandez-Hierro and colleagues using a new method to analyse aflatoxins B1, B2, G1, G2 and oxratoxins based on the methoide of Rafael J. Garcia-Villanova 2004. found that aflatoxins were below these legal limits. Ochratoxin A was found with a mean of 11.8 microgram/kg. A maximum level between 10 and 20 microgram/kg is generally used in commercial transactions. [498] [499]

Past findings of aflatoxin and ochratoxin in spices:


Inactivation of ochratoxin and other mycotoxins in cereals

Heating during cooking and backing does not inactivate ochratoxin.Stored cereals can be decontaminated with an atmosphere of 2% NH3 at 20 degrees during 4 to 6 month. Regarding cost and danger which this decontamination can bear it should always tried to avoid initial contamination of food storing the cereals under proper conditions of humidity and temperature and reducing the storage time.


Harmful chemicals in hatcheries:

Residues of drugs "to prevent diseases" are found in fish meat up to 6 months after administration of the drug. Feed with animal origin with BSE material fed to routs, salmon and eels. Fish of hatcheries being fed with prion contaminated meat is a possible source of human CJD disease. Antibiotics and hormones to speed weight gain are of general concern. Drugs to combat worms are found in samples of fish meat from hatcheries.


Addictive drugs

Some vegetable substances and their derivates are toxic and create addiction, such as excessive consumption of alcohol, smoking or taking drugs.


Alcohol classified as carcinogenic substance

A German commission of the German association of research (Deutsche Forschungsgemeinschaft (DFG) [97]classifying ingredients of working materials has recently classified alcohol as carcinogenic substance[97].
As alcohol is used as cleaning agent such as window cleaning product, disinfection agent in health care and in many other working materials the recent publication has given ground to many discussions about toxicity and addiction.
As the commission was designated to classify working materials she was not allowed to extend their results to food ingredients.
It is obvious that the lobby of beverage industry makes everything possible to avoid the extension of the classification of alcohol in food as carcinogenic and addictive drug.
According to the commission alcohol is transformed in the body to acetaldehyde which on his turn damages the genotype.
The commission of the DFG created a new classification of cancerogenic substances, including alcohol in the " class of substances whose activity is so small that below a maximum concentration on working place (Maximale Arbeitsplatzkonzentration) (MAK) there is no significant risk of cancer expected." This classification includes however also formaldehyde, styrol, lindan and hexachlorbenzol at a concentration below MAK.
The former rule that any cancerogenic substance should be avoided because even a single molecule is able to start cancer is now discarded.
Toxicologists on their turn argue that alcohol is a part of the normal metabolism.
They say: "Resulting cancerogenic activity of normal metabolism is unavoidable. A small increase of the normal level of alcohol due to a limited amount of external origin does not significantly increase the cancer risk." Heavy drinking does significantly increase the risk.


Alcohol as addictive drug

Le Monde presented at the 17.of June 1998 the report of the professor of pharmacy Bernard Roques concerning the risk of addictive drugs[95].
Bernard Roques had been appointed by Kouchner (state minister for health of the Ministry for Work and Solidarity of France ) to name a commission to screen the international scientific literature related to addictive drugs.
Bernhard Rouques is head of a section of of the National Institute for Health and Medical Research (Inserm).
The report was made under his direction.
It is based mainly on medical molecularbiological knowledge. It does not consider historical, psychological and cultural aspects of the consumption of addictive drugs.
Some drugs are still not sufficiently known, such as ecstasy which is feared to produce heavy damage of the nervous system.
Should this fear proof to be true, ecstasy must be inserted in the first group of the very hard addictive drugs.
Having some weak points, however, the Roques - Report is in his basic message correct and represents the trend towards the classification of alcohol as addictive drug.

Health risks of different addictive drugs, according Rouques - Report

Harm Heroin(opiate) Alcohol Cocain
Physical addiction very strong very strong weak
Psychic addiction very strong very strong strong,changing
Neurotoxic weak strong strong
General toxicity strong strong strong
Social danger very strong strong very strong
Treatment chances yes yes yes


Harm Ecstasy psychostimulants benzodiazepine tobacco
Physical addiction very weak weak middle weak
Psychic addiction no informations middle strong very strong
Neurotoxic very strong strong 0 0
General toxicity very strong strong very weak very strong***
Social danger weak weak weak 0
Treatment chances no no no research yes
***Cancer

Harm Cannabinoides
Physical addiction weak
Psychic addiction weak
Neurotoxic 0
General toxicity very weak
Social danger weak
Treatment chances no research


The use and abuse of alcohol in pharmacy

Alcohol is used in many medicaments mainly as solvent and preservative of herb extracts, tinctures, antitussives, tonics, sedatives and many other traditional pharmaceutical preparations and last but not least it is used to improve the taste of certain medicaments. The above mentioned publications are a great challenge to pharmacy to reduce the use or ban alcohol in their preparations because of following reasons:
  1. Alcohol, even in small doses is carcinogenic Alcohol was classified as carcinogenic substance by a German commission of scientists of DFG classifying ingredients of working materials.
  2. Alcohol is an addictive drug of first category The Rouque - Report has classified the dangerousness of alcohol as strong.
  3. Alcohol should not be taken together with certain medicaments. Alcohol is listed in the incompatibility list of medicaments such as antibiotics, neuroleptics and many other. Patients under antibiotics have to avoid tonics or other additional medicaments because of their content of alcohol.


Dioxin in milk

[136] The great demand of orange juice has cause intensive farming of orange trees in Brazil. Derivates of this farming are orange oil and the peel which is dried as pellets used as cattle fodder in Germany.
These Brazilian orange peel pelletsmainly exported by "Coimbra Frutesp" company together with calcium of combustion exhaust washer was responsible to an increase of dioxin levels in milk, butter, cream and meat in Germany. The average level of dioxin in milk was 0,5 Picogramm in one gram fat. In August 1998 this level was three times as high as four month ago. In Süd Baden (Germany) milk with 4,83 Picogramm had to be destroyed as special garbage.
The orange peel pellets from Brazil used as fodder had 147 picogram dioxin per gram.
According to Abecitrus this contamination comes from the use of perchloretylene containing mineral oil used to dry the pellets. Chalk used to wash combustion gases from smokestacks had also been added to the bovine fodder. The real origin of the dioxin in the citrus pellets therefore could not be found.

Dioxin in feed
In the beginning of 2006 pig, poultry and rabbit farms in Europe were supplied with dioxin contaminated feed.

The Netherlands and Belgium announced that some of the meat from contaminated farms was sold in shops over the last two months, but no serious risk to public health was expected.

Tessenderlo, a feed ingredients company was the source of the contamination, blaming an inadequate PCB test which was not suited for testing dioxins as the cause had of the error. The first alert came from pig fat originating from Belgium with 25 times the maximum permitted concentration in pork fat.

Two defective filters at Tessenderlo Chemicals caused an error in the treatment of hydrochloric acid which was then used by PB Gelatin to extract pig fat from the process of making gelatin at PB Gelatins, a unit of Tessenderlo, a Belgian chemical company. The extracted fat was later distributed to animal feed producers such as Leroy and Algoet, it said. The level of toxicity equivalent, or TEQ, in the contaminated fat was 400 picograms per one gram of fat. The maximum acceptable level is 2 picograms.

Dioxin contaminated feed was then distributed to pork farms in Belgium, Germany and The Netherlands.The dioxin was no longer present in subsequent batches of extracted fat at PB Gelatins [153]

Recent meat pollution: Maximum levels of sum of dioxins and dioxin-like PCBs
The European Commission has adopted in 03.02.2006 new implementing legislation setting maximum levels for the sum of dioxins and dioxin-like Polychlorinated Biphenyls (PCBs) in food and feed.

Maximum levels for dioxins in food of animal origin and all animal feed have been applicable since July 2002. However, due to lack of sufficient data and scientific information at the time, no levels were set for dioxin-like PCBs. Since 2002, new data on dioxin-like PCBs has become available, and the legislation adopted today lays down mandatory limits for the combined level of dioxins and dioxin-like PCBs.

From November 2006, any food or feed in which the sum of dioxins and dioxin-like PCBs exceeds these maximum levels will not be allowed to be marketed in the EU. [137]


Food poisoning

Food may contain toxins originated by a biological activity such as mycotoxins, pollutants resulting from pollution of the environment such as dioxins and poisons resulting from human activities such as antibiotics, hormones, antihelmintica and other pesticides (lindane, carbendazim and chlopyrifos) resulting from animal breeding, mercury in fish from industrial sewage,PAC (polycyclic aromatic carbon) resulting from smoke used in food,dioxin (Polychlorated dibenzodioxin PCDD) , dibenzofuran (PCDF), Heavy metals such as arsenic, lead, cadmium, Japan had two great food poisoning:
1954 - contaminated fish with cadmium causing the "Itai-Itai disease. 1968 - contaminated fish with mercury in Minamata, resulting from industrial sewage. Mercury is found in mediteranean fish, such as tuna in concentrations up to 1 mg/Kg. Fish is the most important poison source for mercury.


Changing ecology and toxic foods

The Minamata disease in Japan: The disease was first known in Japan where 1,500 citizens of the small village Kumamoto on the shore of the Minamata bay contracted symptoms in the 1950s after an industrial release of mercury in the waters of the Minamata Bay. The Japanese victims had eaten the mercury contaminated fish.

The disease in Tapajós region: Minamata disease has been found in the fishing communities of the Tapajós River in Brazil's Amazon basin. It causes serious damage to the nervous system, resulting in uncontrollable shaking and muscle wasting. It also produces deformities in the children of offsprings.


Origin of mercury in the Amazon region:

A research team analysing the problem includes specialists in cytogenetics, ethnobotany, biogeochemistry, sociology, the environment, and forestry from the Amazonian Federal University of Pará(UFPa) in Belém, the UFPa outreach campus in Santarém, the Federal University of Rio de Janeiro, UQAM, and the Grupo do Defencia do Amazona in Santarém. Their work is supported by the International Development Research Centre (IDRC).

Gold mining:

Gold-mining activity was blamed to be responsible for the presence of mercury in the Tapajós. Independent miners mixe elemental mercury with river sediments and soil in order to extract the gold. It has been calculated that only 68 tonnes mercury/year due to poorly conducted amalgamation practice by volatilisation during amalgam distillation are liberated in the environment and is left there in the metal form. This is a small amount compared with the size of the problem.

The Minamata cases involve soluble methyl mercury, and the sufferers live hundreds of kilometers from the nearest mine.

The ecology

Slash and burn: In addition, "slash and burn" agricultural practices, leading to large-scale deforestation and erosion of soil heavily laden with natural mercury, are a major source of mercury pollution. The mercury content in wood is about 0.1 to 0.5 ppm. Slash an burn liberates this mercury.

Heavy agricultural activities such as cattle pastures, soybean, maize and cotton plantations will promote further erosion of soil which will increase mercury in the rivers of the Amazon region.

Fish from reservoirs in Northern Manitoba showed high Hg levels. Forest fires may be expected to mobilise Hg contained in biomass and redistribute it into the atmosphere either as vapor or attached to particulates.

Wild forest fires and wood combustion: Wild forest fires are estimated to release 20 tonnes of Hg to the atmosphere, which is less than 1% of natural emissions. Intentional wood combustion represents 60 to 300 tonnes of Hg about 5% of all man-made emission.

Deforestation: The deforestation by fires in the Amazon liberate about 75 tonnes of mercury in the atmosphere every year. The land is generally used for pasture and reburned in a cycle between 2 to 7 years.

Cerrado vegetation, which is mainly grass and bush, covers wide area of Brazil takes up mercury from soil and deposition by rain. Only 10% of the biomass burnt is from the deforestation and 90% is from cerrado burning.

Emission from vegetation: The formation of methylmercury called methylation, in the Amazon region differs from temperate regions due to specific sediments, floating macrophyte mats and flooded soils, together with the unique aquatic and semi-aquatic systems of the Amazon and the high mercury content of organic soils. This favorises the methylation of mercury in the region.

Mercury is present as an environmental contaminant in foods, notably in fish and seafood in the form of methylmercury. Vulnerably groups in particular select fish from a wide rage of species without consuming too much large predatory fish that tend to contain higher levels of methylmercury, such as swordfish and tuna.

The provisional tolerable weekly intake (PTWI) of methylmercury established by FAO/WHO and Food Additives (JECFA) is 1.6 microg/kg body weight. The US National Researche Council has set a maximum of 0.7 $mu$g/kg body weight per week.
Fish as local food: Predator fish contain the highest mercury levels because it has an upper place in the food chain. Eating herbivorous fish and choosing low mercury species the intake of this metal can decrease. The local population, however, eat what they can get and this is most often the predator fish.

Flooded soil Bacteria living in oxygen-starved conditions in river sediments are believed to convert inorganic mercury into the dangerous methylated form. Flooded soils and semi aquatic sediments had higher Hg-methylation potentials than river sediments. The high net Hg-methylation potentials found in newly flooded soils are interesting, because vast areas of the Amazon are flooded in annual cycles.

As we know how dreadful the poisoning with mercury in the bay of Minamata (Japan) was all efforts should be made to avoid a total poisoning of the Amazon region. Gold mining using elementary mercury, deforestation and agriculture causing leaching of mercury should be prohibited.


PCB in fish from the North Sea

According to the Belgian Ministry of Health in June 2000 the amount of PCB ( polychlorinated biphenyl) in fish from the North Sea is in some cases as high as 500 Nanogram in one gram fat.In 30% the upper limit for meat of 200 Nanogram PCB in 1 g fat is surpassed.
The Belgian Health Ministry urges the European Commission to establish an upper limit for PCB in fish.The limit used for meat does not apply for fish because of the low fat content of fish compared to meat. The upper limit for PCB in fish is therefore expected to be set much higher as 200 Nanogramm /g fat.


Poison of heated foods

HAA, Heterocyclic Aromatic Amines: They are cause by heating protein rich foods.They are carcinogenic.
PAK Polycyclic Aromatic Carbon and PAH Polycyclic Aromatic Hydrogen:Thy are formed when fat drips from grill foods and are brought back with smoke and flames contaminating the foods which are done.They are carcinogenic.
To avoid heterocyclic and polycyclic aromatic toxic compounds one should take care not to overheat foods, discard burned parts and refuse smoked food.such as smoked ham.


Hydrocyanic acid

Hydrocyanic acid HCN is a strong poison which is present in certain foods, cigarette smoke and exhaust gases from cars.
Hydrocyanic acid in food is present as hydrocyanic glycoside, nitrilosid or cyanoside. These compound can liberate hydrocyanic acid.
Acute intoxication can be cause by intake of great amount of bitter almonds and some kernels of apricots, cherry, peaches, poppy seed, lima beans and millet. A chronic intoxication can be caused by manioc.


Definitions


Chemical contaminants

: "Contaminant " means any substance not intentionally added to food which is present in food as a result of the production (including operations carried out in crop husbandry and veterinary medicine), manufacture, processing, preparation,treatment, packaging, transport or holding of such food, or as a result of environmental contamination. Extraneous matter, such as, for example, insect fragments, animal hair etc are not covered by this definition (Codex).
Pesticides: Pesticides are substances which are used to prevent, destroy, repel, or mitigate any pest. This includes herbicides, insecticides, fungicides, fumigants and algaecides.
Other contaminants of food: They are found in food, water and environment.
Regulations for pesticides: Important regulations in EU are the Directive 90/642/EC setting Maximum Residue Levels (MRLs) for pesticides on raw agricultural products.
According to Directive 97/41/EC Maximum Residue Levels on processed products should be derived of the MRLs for the raw materials.

Important herbicides:Herbicides are the most widely used pesticides in agriculture.
Herbicide Use as growth control Possible harm
     
Atrazine: Weed in crops of corn, Possible carcinogen.
member of soybeans and sorghum. Harm aquatic microorganism.
steriazine group Inhibit photosynthesis Slight tendency to
    bioaccumulate
     
Metachlor: Grasses and weeds in crops Possible carcinogen.
member of beans,corn, cotton, Moderate toxic to fish.
chloracetamides peanuts, peas, potatoes, It does not bioaccumulate.
  safflower, sorghum, soybeans  
  sunflowers.  
  Perturbe protein synthesis  
     
Alachlor: Grasses and many broadleaf Restrict use because of
member of weeds in crops of beans, corn, groundwater contamination
chloracetamides cotton, milo, peanuts, peas Toxic to saltwater fish and water
  soybeans and sunflower. plants.
  Perturbe protein synthesis.  
     
2,4-D Agrotect: Stimulates plant growth Toxic to fishes and aquatic
member of the hormones (auxin), causing invertebrates. Because these
Chlorophenoxy uncontrolled cell proliferation compounds contain chlorine,
acetic acid Because these compounds they may change to dioxin.
herbicides contain chlorine, they pose  
  a risk for dioxin formation  
     
Trifluralin Grasses and broadleaf weeds in Harmful to fish and aquatic life.
Member of the a variety of tree fruit, nuts Practically non-toxic to man.
Dinitroaniline vegetables and grain crops such The enzymatic process that is
herbicides as soybeans, alfalfa and cotton. disrupted in plants is different
  Nitrosamine in some technical enough from that of humans and
  products. animals that the later experience
    no effects from the chemicals.
     
Glyphosphate: Inhibits synthesis of essential Glyphosate is probably not a
Member of the aminoacids and promotes carcinogen, group E. Possibility
Organophosphate destruction of photosynthetic for toxicity when glyphosate is
herbicides(non- pigments in foliage applied to aquatic environments.
nitrogen based    
herbicides a) Isopropylamine salt, control According to Myriam
  of weeds in broadleaf and Fernandez of the Semiarid
  grasses. Prairie Agricultural Researche
Centre in Swift Current    
  b) Sodium salt, growth regulator Saskatchewan, glyphosate-
  for peanuts and sugar cane. treated wheat appeared to have
    higher levels of Fusarium head
  c) Monoammonium salt, control blight (a toxic fungal disease)
  of weeds in tea plantation, that wheat fields where on
  orchards, rubber, plantation glyphosate had been applied.
  corn, sugarcane and forests.  
     
Dicamba: Broadleaf weeds, Chickweed, Dicamba is not carcinogenic
Member of the mayweed and bindweed in  
benzoic acid and cereals and other related crops  
and analogue    
herbicides    
     
Cyanazine and Grasses and broadleaf weeds in Cyanazine: Cancer-causing
simazine: cereals, cotton, maize, onions potential in experimental
Members of the peanuts, peas, potatoes, animals and possible risks to
s-triazine soybeans, sugar cane and wheat humans. The rat strain used was
herbicides fallow predisposed to develop the
    mammary tumours observed.
    Practically nontoxic.
     
2,4,5-T Stimulate plant growth May lead to teratogenic effects
Member of the hormones (auxin), causing in mammals.
chlorinated uncontrolled cell proliferation  
phenoxyalkanoic Because these compounds  
aciherbicideses contain chlorine, they pose a  
acid herbicides risk for dioxin formation  


Insecticide Insecticide Breakdown Remarks
groups      
       
Organophosphates Malathion Easy No residues in crops, not stored
  Ethyl-   in animal tissue.
  parathion    
  Diazinon   These pesticides affect the
      nervous system by disrupting the
      enzyme that regulates
      acetylcholine, a neurotransmitter.
      Most organophosphates are
      insecticides. They were
      developed during the early 19th
      century, but their effects on
      insects, which are similar to their
      effects on humans, were
      discovered in 1932. Some are
      very poisonous (they were used
      in World War II as nerve agents).
      However, they usually are not
      persistentin the environment.
       
Organosulfurs Tetradifon    
       
Carbamates Carbaryl Degradade They are a danger to many useful
    rapidly in the insects, especially honeybees.
    environment They affect the nervous system
      by disrupting an enzyme that
      regulates acetylcholine, a
      neurotransmitter. The enzyme
      effects are usually reversible.
      There are several subgroups
      within the carbamates
       
Formamidines Amitzaz    
       
Dinitrophenols 2,4    
  Dinitrophenol    
       
Organotins Cyhexatin    
       
Pyrethroids Permethrin   Pyrethroid Pesticides were
      developed as a synthetic version
      of the naturally occurring
      pesticide pyrethrin, which is
      found in chrysanthemums. They
      have been modified to increase
      their stability in the environment.
      Some synthetic pyrethroids are
      toxic to the nervous system
       
Nicotinoids Imidacloprid    
  (Gaucho)    
  Acetaprimid    
       
Fiproles Fipronil    
       
Pyrroles Chlorofenapyr    
       
Pyrazoles Tebufenpyrad    
       
Pyridazinones Pyridaben   No residues in crops, not stored
      in animal tissue
       
Chlorinated   Persistence - Accumulate in the fat tissue. Harms
hydrocarbons   its resistance fishes, earthworms, and robins.
(DDT) or organo   to breakdown They were commonly used in the
chlorines(Such as   in the past, but many have been
DDT, HCC,   environment removed from the market due to
Dieldrin,   is enormous their health and environmental
Toxophene     effects and their persistence (e.g.
      DDT and chlordane


Botanicals (Plant Insecticide Extracted from
extracts)    
     
     
Pyrethrum Pyrethrum Flowers of a
    Chrisanthenum. Kenia and
    Ecuador
     
Nicotine Nicotine Tobacco
     
Rotenone Rotenone Legumes
     
Limonene Limonene Citrus peel


Fumigants Insecticide Remarks
     
     
(They become gas above Methylbromide The most frequent used
40C and contain the   fumigants
halogens Cl, Br or F    
     
Ethylene dichloride Ethylene dichloride  
     
Phosphine gas (PH$_{3}$) Phosphine gas (PH$_{3}$)  


Insect repellents: Before a more edified approach to insect olfaction and behaviour was developed, it was assumed that if a substance was repugnant to humans it would likewise be repellent to insects.
Repellent Registration Agent Remarks
       
       
Benzyl benzoate Registration lost    
Indalone Registration lost    
Rutgers 612 Registration lost    
Dibutyl phtalate Registration lost    
       
MGK repellent 326 Registration lost Dipropyl It is used to expand
  Potential cancer isocinchomeronate the repellency of
  risk.New analysis   DEET, MGK 264,
  of risk   pyrethroids, and
      other active ingredients.
       
N-butyl acetanilide Registration lost   Repellent for
      military clothes
       
Dimelone Registration lost Dimethylcarbamate  
       
DEET, Delphene(r) Still registrated N,N-Dimethyl-meta- DEET is used
    toluamide worldwide for
      biting flies and
      mosquitos.No harm
      if used as labelled.


Bananas and chemicals: United Fruit Company used pesticides like Counter and Mocap (Nematicide-Insecticide). They are being sprayed by crop planes. Honduras and Costa Rica are strongly affected by the way United Fruit handles pesticide programs and social affairs.


Chemicals used in Water treatment

Algaecides: Chelated Complex Copper Algaecide in 9 percent formulation for very effective control of a broad range of planktonic, filamentous and macro algae. Copper sulfate is also used as bactericide.


Other aquatic herbicides

Fluridone: It is a systemic herbicide that kills the entire plant and is generally nonselective since most submersed plants will be killed or affected by a whole lake treatment. It inhibits the formation of carotene, chlorophyll without the protection of carotene is then degraded by sunlight.
The contact time between the plant and Fluridone must be maintained for many weeks, otherwise the plant can regenerate.

There are no swimming, fishing or drinking water restrictions for the application of Fluridone. It is moderately persistent in water of ponds and lakes. Average half-life in pond water is 21 days and 90 days in sediments, being degraded by sunlight and bacteria. Residues may persist longer depending on the amount of sunlight and the water temperature. Fluridone is not considered to be a carcinogen or mutagen and is not associated with reproductive or developmental effects in test animals.
Treated water should not be used for irrigation for thirty days because some terrestrial plants may be damaged, even by low concentrations of Fluridone.

Glyphosate for aquatic use: It is the same active ingredient of Roundup. It has been formulated for safe aquatic use. It is very effective for emerged aquatic weed control and shoreline vegetation.

Granular 2,4-D and liquid 2,4-D Amine: It is effective for control of many submerged, emerged and floating aquatic weeds. 2,4-D kills the entire plant, what is called to be a systemic herbicideindexHerbicide, systemic, acting as stimulant of plant stem elongation. It generally targets the broad-leaved plants (dicots) such as milfoil. Most other aquatic plants are monocots (grass-like) which are not affected by 2,4-D.

Cutrine: It is a chelated copper which stays in solution to continue controlling a broad range of algae long after application. There are no water use restrictions after application. Cutrine is used to control planktonic and filamentous algae, Phythophora, diatoms Chara, Nitella and Hydrilla verticillata. It was used in trout raceways and irrigation canals and is the favourite algaecide for fish farms.It is also being used to reduce secondary bacterial or fungal infections by reducing the phytoplanctonic irritants exposing the gill surface of the fish.

Diquat dibromide: It is a quarternary ammonium herbicide for watermilfoil, Parrot Feather (Myriophyllum), Hydrilla, Water Hyacinth, Water Lettuce, Giant Salvinia and Brazilian Elodea.

Diquat is often used to dessicate potato vines to make harvesting of underground tubers easier. It also promotes peridem formation in the tubers. Diquat should not be applied to potatoes if the soil is very dry, because under such conditions, the water may move from the shoots to the tubers via xylem instead of the normal opposite direction. Tubers, close to the surface become green, treated with Diquat, they may be damaged.
Diquat is nonselective, any plant can be damaged when light and chlorophyl is present.


Inorganic Insecticides

Sulfur: Sulfur is the oldest known, effective insecticide. Sulfur and sulfur candles were burned in the past for every purpose. Sulfur is used in integrated pest management programs targeting specific pests.

Sulfur dusts are especially toxic to mites of every variety, such as chiggers and spider mites, and to thrips and newly-hatched scale insects. Sulfur dusts are also used as fungicides, such as powdery mildews.
Mercury: Very toxic.
Boron: Boric acid is being used against cockroaches and other crawling household insects.

Sodium borate: It is being used to treat lumber and other wood products to control decay by fungi, termites and other wood infesting pests.
Thalium:

Arsenics: Copper arsenate, Paris green, lead arsenate and calcium arsenate. The arsenicals uncouple oxidative phosphorylation, inhibit certain enzymes that contain sulfidryl (-SH) groups and coagulate protein by causing the shape or configuration of proteins to change.

Antimony

Fluoride: Sodium fluoride, barium fluosilicate, sodium silicofluoride and cryolite are used as insecticides. Cryolite is a relative safe fruit and vegetable insecticide used in integrated pest management programs.

Silica gels or silica aerogels: Silica dusts are light, white, fluffy and are used in combination with pyrethrum in household insect control.

Miscellaneous compounds

Pyriproxyfen: It is a pyridine.

Buprofezin: It is a thiadiazine. Both are used to control the whitfly complex, a universal problem in cotton farming.

Clofentezine: It is a member of the group of the tetrazines, used as an acaricide/ovocide for fruits, citrus, cotton, cucurbits, vines and ornamentals,inhibiting mite growth.

Enzone(r) sodium tetrathiocarbonate: It is used only on grapes and citrus applied as a water application and irrigated into the soil. It breaks down in the soil to form carbon disulfide, which acts rapidly, decomposes quickly being active against nematodes, soil insects and soil borne diseases.

Clandosan(r): It is dried, powdered, chitin protein isolated from crustacean exoskeletons and blended with urea. It stimulates growth of beneficial soil microorganisms that control nematodes, but does not have a direct adverse effect on nematodes as such.

Other contaminants

The Regulation 466/2001/EC sets maximum for other contaminants in foodstuffs. Relevant for palmoil is the maximum level of lead in fats and oils for human consumption of 0,1 mg/KG.
The regulation 2375/2001/EC sets maximum levels for dioxinsin fats and oils meant for human consumption. In this regulation the limit for dioxin is set at 0,75 pg/g for all vegetable oils.
Copper: Various copper salts, including basic copper sulfate, coppersulfatechloride, -carbonate, -hydroxide and -oxychloride are able to cause serious intoxication
Ingestion of food, water and beverages,contaminated with copper have been related. Soft drinks like orange juice dispensed in contact with chromium plated copper tubes have cau