Toxicity pesticide residues

Eat organic as much as possible. Fruit, vegetables, grains, and other foods tend to be heavily sprayed. By choosing organic food, you ll reduce your exposure to acid-forming and toxic pesticide residues. 

On-line LC-GC has frequently been used as a clean-up technique for the analysis of trace levels of contaminants (pesticides, plasticizers, dyestuffs and toxic organic chemicals) in water and food products. Several different approaches have been proposed for the analysis of contaminants by on-line LC-GC. Since pesticide residues occur at low concentration in water, soil or food, extraction and concentration is needed before GC analysis is carried out. 

We hear and read a lot these days about the dangers of "chemicals"—about pesticide residues on our food, toxic wastes on our land, unsafe medicines, and so forth. What s a person to believe ... 

In many cases, there is difficulty in preserving residues in samples after collection and prior to pesticide analysis which coincides with a rapid further degradation and mineralization of the pesticide residues under most environmental conditions. Storage stability studies and studies on the reactivity of sample collection equipment in addition to field quality assurance procedures can help address some of these questions. Concerns are accentuated for compounds that have short half-lives in the environment but still have high acute toxicity. 

This document deals only with estimating exposure to direct additives and chemical contaminants. The procedures used to estimate exposure to chemical contaminants in food (including naturally occurring toxicants, such as mycotoxins) are essentially the same as those used for direct additives. Thus, contaminants will be considered in the discussion of direct additive exposure estimation. The procedures discussed herein are equally applicable to color additives, GRAS substances, prior-sanctioned ingredients, and pesticide residues. 

A Division of Pharmacology had been formally set up in the Food and Drug Administration in 1935, composed mostly—as one of its members, Edwin P. Laug, remembered—of "biochemists who then changed sails and became pharmacologists" (7] ). To study the toxicity of lead and arsenic pesticide residues formed the division s initial purpose, but the Elixir Sulfanilamide crisis brought an almost total shift of effort to diethylene glycol. 

Usually, only small fractions of applied pesticides reach the target organisms, the majority of the chemicals being distributed to the air, soil, and water. On such release, many nontarget organisms can be affected severely. Pesticide residues and their degradation products are toxic to many components of ecological systems. 

Finally, an equally Important component of ground water risk assessment Is toxicity. Only rarely have levels of pesticides In well water been detected which would cause acute toxicity, unless Improper disposal caused the contamination. Rather, as can be seen In Table III, the pesticide levels are usually In the low ppb range. Therefore, our current toxicity concerns are usually for chronic human toxicity or, occasionally, aquatic toxicity. There Is also the possibility of organisms receiving toxic amounts of pesticide residues over time via blomagnlf1catIon. 

Toxicological evaluations of food additives and of contaminants, naturally occurring toxicants and residues of veterinary drugs in food produced by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), and of pesticide residues in food by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) are used by the Codex Alimentarius Commission and national governments to set international food standards and safe levels for protection of the consumer. 

The use of pesticides in agriculture has obvious advantages, such as an increase in the quantity and quality of food crops. Nevertheless, pesticides are toxic substances, and their residues can pose a risk to man and environment. Therefore, pesticide residues in food are regulated at the international and national levels according to the toxicity of the compound and the human intake of a particular crop. The acute oral toxicity for rats and the maximum residue levels (MRLs) of carbamate and urea pesticides are listed in Tables 1 and 2. 

Pesticide residues in food in the developed world are extremely unlikely to ever have caused acute illness. Their levels are so low and relatively infrequent that it would be impossible to consume sufficient food to attain an intake of pesticides that even approached toxic levels. The chronic effects of pesticide residues, in particular mixed residues, is very much more difficult to assess in terms of biological effects on the consumer. We know very little about the synergistic or additive toxicological effects of pesticide residues, but we do know that in every meal that we consume it is very likely that more than one pesticide will be present, albeit at a vanishingly low concentration. 

Toxic chemical intake must be quantified in order that comparisons between different chemicals (e.g. pesticides), diets and countries can be made. Most countries in the developed world conduct surveys which involve analysing food for pesticide residues. These values are then put in context by comparing them to benchmarks of toxicity (Acceptable Daily Intake - ADI) or with trading standards (Maximum Residue Level -MRL) which are set to ensure that countries exporting food do not export excessive pesticide residues with that food. 

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