The Poison in the Food Chain

One of the most sinister features of DDT and related chemicals is the way they are passed

on from one organism to another through all the links of the food chains. For example,

fields of alfalfa are dusted with DDT. Meal is later prepared from the alfalfa

and fed to hens. The hens lay eggs which contain DDT. Or the hay containing residues of seven

to eight parts per million may be fed to cows. The DDT will turn up in the milk in

the amount of about three parts per million, but in butter made from this milk,

the concentration may run to 65 parts per million. Through such a process of transfer,

what started out as a very small amount of DDT may end as a heavy concentration.