Since the mid-1970s, attention has been focused
on the possible health implications of
long-term environmental exposure to low level
heavy metals, particularly lead (Servant 1986;
Culbard et al., 1988). Lead and its organic compounds
are toxic. They are cumulative toxins
which can enter the body by inhalation of dust,
fumes and vapour or by ingestion (Folinsbee,
1993).