Pesticides and Health

Humans are exposed to pesticides in a number of ways.

Those occupationally engaged in pesticide production or application will receive the highest exposures.

In developing countries, including China, many farm workers apply pesticides without wearing protective clothing and using knapsack sprayers which may be leaking.

The incidence of acute poisonings is high.

Those not working with pesticides will still be exposed to pesticides through the air they breathe, the water they drink and the food they eat.

Pesticides do not break down immediately after use but may remain stable and active for days, months, or many years depending on the pesticide.

Food crops contain residues of the pesticides applied to them while in the field.

Harvest intervals establish the period of time which should pass after the application of a particular pesticide and before the crop can be harvested.

However, these may not be adhered to, and even where they are, residues may remain on food products.

In addition, crops may be sprayed after harvest to prevent them from ‘spoiling’ during storage and transit.

Pesticide applied to land may travel down through the soil profile reaching the water table below.

After rain pesticides may be washed off land into nearby streams or lakes.

Drinking water abstracted from these sources will contain residues of the pesticides applied to fields.

Those living near sprayed fields may be exposed by breathing in air carrying residues of pesticides.