An interactive guide about how the environment, chemicals and toxic substances affect human health.

Other chemicals could affect sites that determine whether genes are expressed.

The chemicals in turn contaminate fish and move up the food chain, affecting birds as well.

These chemicals affect the transmission of nerve impulses to muscle.

This study presents a number of hypotheses for how these chemicals affect the endocrine system.

These chemicals affect the brain similarly to some medications used for Parkinson's disease.

Some known chemicals and elements can also affect deafness in animals.

These chemicals affect all stages of the life cycle because they target the nervous system.

However, researchers do not know how the chemicals affect the lungs and what can cause them to trigger asthma.

It is possible, however, that synthetic chemicals might affect the immune response in some way.