The changing attitudes to pesticides and pharmaceutical drugs

The acceptance of the government s role in protecting the public from hazards 

The rising concern about toxic chemicals in foods 

DDT was not the only synthetic chemical to find a use in private and commercial gardens. Plant physiologists in the 1930s had accidentally discovered a way of selectively killing weeds in cereal crops (the dominant source of food for humans— wheat, barley, maize and rice). The plant physiologists interested in how plants controlled their growth had discovered a plant hormone—auxin (indole-3-acetic acid). Chemists soon found that, not only was it easy to make this compound, but they could also easily make 

Residues Food crops 1 ppm Food crops 0.1 ppm Meat 0.1 ppm Milk 0.1 ppm Food crops 0.01 ppm Meat 0.1 ppm Milk 0.005 ppm 

Ecology None None Environmental stability Environmental movement Accumulation Total effects on all non-target species 

---