Table of Contents
This content is being optimised
Food contamination refers to the presence in food of harmful chemicals and microorganisms which can cause consumer illness.
Substance added intentionally or unintentionally that
(1) makes food unfit for human consumption, such as animal droppings, biocides, disease-causing microorganisms or insects, dust, pests, and other foreign bodies or impurities,
(2) is added only to increase the bulk or weight of food, such as water in milk and starch in ketchup, or
(3) is food but is in wrong places, such as a bean in a can of peas.
Pesticide Residues
Pesticides are chemicals used in agriculture to protect crops against insects, fungi, weeds and other pests. In addition to their use in agriculture, pesticides are also used to protect public health in controlling the vectors of tropical diseases, such as mosquitoes.
Bacterial toxins mycotoxins
It is difficult to define mycotoxin in a few words. All mycotoxins are low-molecular-weight natural products (i.e., small molecules) produced as secondary metabolites by filamentous fungi. These metabolites constitute a toxigenically and chemically heterogeneous assemblage that are grouped together only because the members can cause disease and death in human beings and other vertebrates.
Animal and human health problems related to food products contaminated with toxic metabolites produced by fungal growth have long been recognized. The Food and Agriculture Organization has estimated that at least 25% of the world’s food crops are affected by mycotoxins annually. Thus, many scientific reports have been published concerning the occurrence of mycotoxins in foods and feeds, and their impact on human and animal health. Recently, there have been reports on contamination of various toxins, i.e., aflatoxin B1/fumonisin B1 and ochratoxin A/aflatoxin B1, among others. Although more documentation is needed on the levels and effects of mycotoxin contamination it is important to consider that food commodities are a complex environment and that the individual effect of each toxin might be affected by the presence of other toxins or food constituents.
These toxins account for millions of dollars annually in losses worldwide in human health, animal health, and condemned agricultural products. Factors contributing to the presence or production of mycotoxins in foods or feeds include storage, environmental, and ecological conditions. Often times most factors are beyond human control Ochratoxin A (OTA) is a secondary metabolite produced by several species of Aspergillus and Penicillium. The toxin, which is a nephrotoxic and nephrocarcinogenic compound, has mainly been found in cereals as well as in other products like coffee, wine, dried fruits, beer and grape juice. It occurs in the kidney, liver and blood of farm animals by transfer from animal feed.Human food can be contaminated with mycotoxins at various stages in the food chain
Seafood toxins
Metallic Contaminants
Metals such as arsenic, cadmium, lead and mercury etc. are naturally occurring chemical compounds. They can be present at various levels in the environment, e.g. soil, water and atmosphere. Metals can also occur as residues in food because of their presence in the environment, as a result of human activities such as farming, industry or car exhausts or from contamination during food processing and storage. People can be exposed to these metals from the environment or by ingesting contaminated food or water. Their accumulation in the body can lead to harmful effects over time.
Nickel
Nickel is a naturally occurring metal that is sometimes present in food and water through environmental contamination, including as a result of human activity. Short-term (‘acute’) exposure to nickel causes allergic reactions in some individuals, both by touch and also from ingestion in food or water. The results of animal studies also indicate possible reproductive and developmental effects from long-term (‘chronic’) exposure to nickel.
Lead
Lead can enter the human food chain as a result of human activity with the environment. For example, lead residues present in soil can contaminate vegetables. As for example, the recent Maggi incident, where the level of lead contamination was found to be higher than permissible limits, most probably arose from the lead-contaminated soil where the main raw material i.e. wheat, is grown. Lead can also contaminate aquatic life such as fishes that are consumed as food.
Copper
Although copper is an essential element, it can be toxic to humans at high levels i.e. above the recommended permissible limits. Copper contamination of food can occur if the cooking utensils, including pots and pans, are made of uncoated copper, especially if acidic foods are cooked. Copper can also enter the human food chain through the use of copper-containing fungicides.
- Health Hazards: Chronic exposure to copper can cause liver failure.
Tin
The use of tin cans for packaging foods and beverages can lead to contamination with tin. Therefore, avoiding canned food would be a good idea to reduce the risk of tin poisoning. Tin can also enter food through the use of tin-containing organo-pesticides.
Cadmium
Cadmium can enter the body through food crops via contaminated soil and water. Kidney of food animals such as goats and sheep can contain high levels of cadmium. This metal can also be found in molluscs and crustaceans. Cadmium can also be present in chocolate-based sweets and candies.
Chromium
Chromium can be generated by industrial processes and manufacturing activities. It can contaminate groundwater by poor storage, leakage and improper disposal practices, as a result of which the drinking water can become contaminated.
Residues from packaging material