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Lecture Objectives

• List and describe the microbial found in . • Explain the potential for environmental toxins to cause unintended Food I hazards. Lecture 11 • Recognize that many foods contain natural hazards which pose health risks. • Describe the conditions associated with the microbial, environmental, and natural toxins.

Microbial Toxins in Foods Fungi -

• Microbial toxins commonly found • Mycotoxins are toxic substances in foods include: produced by some fungi. The • Mycotoxins (fungi) following mycotoxins may be • Scombroid (histamine – producing found in foods: bacteria) • – produced by Aspergillus • Ciguatoxin (algae) flavus (seen on corn and under a • Paralytic (algae) microscope at right) • – produced by Claviceps • Note: The toxins produced by purpurea. Clostridium botulinum, • Intestinal irritants – produced by Staphylococcus aureus, and poisonous mushrooms. Bacillus cereus were discussed in Fungal spores are easily spread due in part to their small size. early lectures. NCSU – Plant Pathology Extension

Mycotoxin- Aflatoxin - Aflatoxin

• Aspergillus flavus produces • In 2013 there was a recall of dog a called aflatoxin foods contaminated with which causes an aflatoxin. intoxication. • Drought conditions resulted in • Found in moldy grains and overgrowth of Aspergillus nuts including corn and on corn. pistachios, and also found in peanuts and soy. • That corn was used to produce dog food. • Can cause severe liver damage including cirrhosis, Aspergillus fungus –Iowa State University. necrosis, and carcinoma. • Often fatal.

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Mycotoxin - Aflatoxin Mycotoxins - Ergot

• Ergot is a toxin produced by the fungus that infects . • The toxins have hallucinogenic properties. • Causes a syndrome known In the United States we routinely test foods for aflatoxin and human cases are rare. In as or “St. Vitus places where detection is not used, large outbreaks with high numbers of deaths (125 Dance” which includes Claviceps purpurea fungus on rye. above) can occur. Note the cause of this outbreak was contaminated corn. and .

Mycotoxins - Ergot Mycotoxins - Mushrooms

• In Salem, Massachusetts in • Poisonous mushrooms often look 1692 several women were similar to hallucinogenic accused of being witches mushrooms. after exhibiting strange • Persons who abuse mushrooms symptoms (hallucinations often mistakenly eat the wrong and spasms). ones. • 20 people were executed. • The mushrooms commonly produce gastrointestinal irritants • Ergot is known to have (compounds that produce rapid, infected rye in Salem, MA, transient , , leading some to speculate abdominal cramping, and Fans of eating wild mushrooms are quick to point out that the “witches” were in ). that some species are poisonous. fact victims. Memorial to the victims of the Salem witch trials. • Some of the mushrooms are deadly.

Poisonous Mushrooms Scombroid Poisoning

• In this outbreak in 2012, a caregiver • Intoxication is caused by ingesting accidentally used poisonous large amounts of the chemical mushrooms to make a soup for histamine which is produced by elderly patients. bacteria in . – , mahi-mahi, sardines, etc. • Four people died and several others – Usually results from fish being held at became ill. high temperatures for long time periods (temperature abuse). • Toxin is heat-stable. • In other words, it may not be destroyed by cooking. • Symptoms include dizziness, burning, rash, , and can be fatal. • Severe cases may require treatment with fast-acting antihistamines.

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Scombroid Poisoning – Tuna Steaks Algal Toxins

• The algae rarely cause disease and foodborne infection due to algae is rare. Most cases are due to the following two types of toxins: • Ciguatoxin • Paralytic (PSP toxins). • Amnesic Shellfish Poisoning.

NOAA – National Oceanic and Atmospheric Administration Center. Imported tuna was a common food in these outbreak but elevated levels of histamine were not detected in remaining samples. The source remains unknown.

Ciguatoxin - Algae Ciguatera – Algae (continued)

• Ciguatoxin is produced by algae • Human cases of ciguatera (the ( – in photo at right). disease caused by ciguatoxin) usually occur following ingestion • The algae are eaten by fish, which are of barracuda, snapper, jack & in turn eaten by larger fish, causing . the toxin to accumulate to dangerous • Cases are common in Hawaii levels in large fish (a process known and Puerto Rico. as bioaccumulation). • However, if the fish are shipped • Prevention is eating smaller fish. cases can occur anywhere. In the report at right, cases occurred in • Symptoms include nausea, diarrhea, New York City. The distributor of vomiting, headache, excessive the fish is not named but reports sweating, weakness, itching, etc. show that they had already been issued a warning! • There is no specific treatment and disease is rarely fatal.

Shellfish Toxins - Algae

• Produced by several types of algae including the species that causes “”. • The toxins are heat-stable (in other words, cooking does NOT destroy them). • Infects , , , crabs, and . • Symptoms can be confused with shellfish allergies: • Numbness, tingling occur first. Ciguatoxin caused a • Headache, dizziness, nausea. heart attack that • In severe cases, muscle paralysis and respiratory failure occur. killed a woman who • death occurs within 2-25 hours. ate grouper in Mexico.

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Paralytic Shellfish Poisoning - Algae Amnesic Shellfish Poisoning - Algae

• Most PSP cases occur in colder climates where the toxin (from the algae) accumulates in the shellfish. • Saxotoxin is most common. • Death can occur within 3 to 4 hours due to respiratory paralysis.

Caused by domoicacid, this toxin produced by algae can cause severe neurological damage, including loss of Alaska Public Media short term memory.

Environmental Toxins Environmental Toxins - Persistence

• Industrial processes can release • Persistence of toxins refers to the contaminants into the extent to which the toxin lingers environment. in the environment or in the • Polluted air, water, and soil can body. result in contaminated produce, • Contaminants present for a short dairy, meats, and seafood. time or eliminated by the body • Some environmental pose little health risk. contaminants can cause health • Contaminants which persist may problems. also bioaccumulate.

Figure produced by University of Maine using FDA contamination level data.

Environmental Toxins - Bioaccumulation Environmental Toxins - PBTs

• Some toxins do not breakdown in • The Environmental Protection the environment. Agency has identified a number of persistent, bioaccumulative, • These toxins move up through the highly toxic chemicals it is food chain and they accumulate. committed to removing from the • Each level has a higher environment. concentration than the one below. • These compounds pose a health • Eventually humans consume a risk to both humans and food which contains high levels of ecosystems through food and a toxin such as in tuna. water. • The top priority PBTs (persistent, bioaccumulative, toxins) are shown at right.

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Environmental Toxins - PBTs Environmental Toxins – PBTs (continued)

• Aldrin/ – Insecticide – • Mercury – discussed on next banned 1985. slides. • Benzo(a)pyrene – product of incomplete combustion – exposed • Mirex – insecticide – banned due to fires, smoked foods, etc. 1978. • Chlordane – – banned 1988. • Octachlorstyrene– formed during • DDT, DDP, DDE – – banned the production of magnesium. 1972. • PCBs – discussed on next slides. • Hexachlorobenzene – pesticide – banned 1965. • Dioxins and Furans – discussed on • Alkyl-lead – fuel additive – banned next slides. from automobiles but used in limited • Toxaphene – insecticide – banned capacity (racing, marine, aircraft). 1980.

Environmental Toxins - Mercury Lecture Note - Mercury

• Mercury is an element and it is used in • Exposure to methylmercury results in • Mercury is used in many the production of many products: impaired neurological development in pharmaceuticals as a • Chemicals the fetus: . • Pharmaceuticals • Cognitive thinking • Switches • Memory • Added to multi-use vials to prevent • Thermometers • Attention the growth of . • Light bulbs • Language • The form of mercury used in these • Once mercury enters the environment, • Fine motor skills applications is ethyl mercury (not microorganisms convert it to • Visual spatial skills methylmercury). Thimerosal, the component used in vaccines that many methylmercury which is the highly toxic believe causes autism despite studies demonstrating that mercury that builds up in fish and this is not true. shellfish.

Methyl – Environmental Toxins - PCBs

• Between 1932 and 1968, a • PCBs are chlorinated • PCBs exert toxic effects on the petrochemical and plastics hydrocarbons that were used in following body systems (in manufacturer dumped an 100s of industrial and commercial addition to causing cancers): estimated 27 tons of mercury in applications. • Immune system Minamata bay (Japan). • PCBs are known to cause cancer • Endocrine system • Poisoning the fish and the people in animals. • Reproductive system who ate the fish. • • Over 900 deaths. • PCBs were banned in 1979 in the • Over 2 million people suffer(ed) United States but they do not chronic health problems. breakdown and can be found: • In the environment • In wildlife tissues • In the food chain.

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Environmental Toxins – Dioxins and Furans Dioxin Poisoning – Yusho Disease

• Refers to a family of toxic • Health effects include the • In 1968 in Japan a number of • Despite the knowledge gained substances that have similar following: patients were reported to have from this outbreak, the same thing chemical structures. • Chloracne (below), and other skin symptoms including acne-like happened in Taiwan in 1979. • They are the byproducts of conditions. eruptions, pigmentation of the industrial processes or are • Immune system damage skin, and eye discharge. creating during burning: • Developmental damage • The cause of the disease was later • Reproductive damage • Burning of waste found to be rice oil (Yusho means • Cancer • Burning of wood oil disease) contaminated with • Found in the food chain in meat dioxin-related compounds. and dairy. • A total of 1961 people are • Due to accumulation in the registered as yusho patients. environment.

Natural Toxins Natural Toxins - Goitrogens

• A number of plants contain • Goitrogens can cause enlargement of the thyroid gland by blocking the natural toxins. uptake of iodine. • Many of these toxins are designed to protect the plants from insect • Found in very small amounts in a damage. large number of foods: • Cabbage • These toxins are not harmful if • Bok choy ingested in small amounts. • Turnips • The most common are: • Mustard greens • Kale • Goitrogens • Brussels sprouts • Cyanogens • Cauliflower

• Solanine These foods contain cyanogens. Tapioca could potentially kill you, just • Broccoli ask Sheldon Cooper: https://www.youtube.com/watch?v=JeLlLgI0U4Y • Kohlrabi • Radishes

Natural Toxins - Cyanogens Cyanogen Poisoning – Cassava - Konzo

• Some foods contain cyanogens • Konzo disease is a neuromotor which can convert to : disease caused by exposure to • Apricot pits cyanogen in cassava. • Peach pits • Altered gait • Apple seeds • Spastic movements • Lima beans • Cognitive disorders • Cassava • Occurs when cassava is not • Lima beans with low levels of processed properly to break cyanogens are used in foods. down the cyanogens. • Most people do not eat seeds (a few will not hurt you) and pits of fruits.

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Natural Toxins – Cyanogens - Laetrile Natural Toxins - Solanine

• Solanine is a narcotic-like poison found in potatoes: • Largely in the leaves and stems but to Despite the warnings that a limited amount in the peel. laetrile, derived from apricot • Poisoning is rare except in times of pits is NOT a cure for cancer food shortage. and is in fact poisonous, a • Symptoms include: quick search in Amazon • Vomiting results in a product for sale. • Diarrhea • Abdominal pain • Coma • Convulsive twitching • Confusion • • Death is rare unless the person is dehydrated.

Lecture Summary

• Lecture Note: Information used in this lecture on Environmental Toxins was adapted from the Environmental Protection Agency Website (www.epa.gov). • Foods are susceptible to toxic contamination from microbial, environmental, and natural toxins. • The symptoms depend on the toxin present and there are few treatment options. • Protecting the food supply from toxic contamination requires adherence to regulatory guidelines.

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