Lead is a familiar example of the consequences of the connectedness in our environment. It is used in plumbing and was made into drinking vessels in Roman times. It is in crystal, cans, paint and glazes.

Although banned in 1978, leaded paint is still present in older homes. More than 80 per cent of US homes built before 1978 - some 64 million - contain lead paint. (Environmental Health Threats to Children, p. 3).

Whether in poorly maintained homes or and in homes in restoration, lead-containing paint chips become airborne in the breathing space for a brief time, and then end up in nearby soil. Lead from gasoline emissions, regulated in 1973, precipitated out of the air and was captured in the soil. Lead in soil does not decompose.

The remedies for lead contamination also have a chain: prevention, education, screening (both the patient and the source), mitigation or treatment (in the individual and the environment), and authority for regulatory and remedial action in public policy.