Lead has been known and used by man for thousands of years and its tox
ic properties have been known for almost as long. In consequence, a wi
de body of legislation has built up and is designed to protect individ
uals in both the occupational and the general environments. At the occ
upational level, two types of controls are widely employed, namely, le
ad-in-air and lead-in-blood. Limits placed on the amount of lead-in-ai
r are designed to ensure that individuals are not exposed to unsafe le
vels of lead via inhalation. Currently, the most common standard is 0.
15 mg m(-3) but then is a clear downward trend and levels as low as 0.
05 mg m(-3) are mandatory in some countries. Controls on the amount of
lead-in-blood give a more direct indication of the exposure experienc
ed by individuals. The most common level presently employed is 70 mu g
m(-3) but, as knowledge of the health effects of lead improves, lower
levels are being introduced and 50 mu g m(-3) is now fairly common. W
hile women are no more sensitive to lead than men, some countries do e
mploy lower blood-lead limits for women in the workplace in order to p
rotect any developing foetus. This paper examines the levels currently
in force in various countries and describes developments which are no
w taking place in the legislation that is being enacted in several par
ts of the world. As far as the general public is concerned, only a rel
atively small number of countries employ controls. Where controls do e
xist, however, they are set at much lower levels than for the occupati
onal environment in order to protect the most sensitive members of the
population. Several countries employ limits on lead in ambient air. T
raditionally, these have been set at either 1.5 or 2.0 mu g m(-3), but
several countries are currently considering sharp downward revisions
to levels of the order of 0.5 mu g m(-3). A few countries offer guidan
ce on acceptable blood levels for the general population, most commonl
y for children. Again downward revisions are taking place but where da
ta are available, there is a very encouraging downward trend also in a
verage blood-lead levels found amongst members of the population. Thes
e must be due to a combination of factors which have reduced exposures
to lead. The net result is that, at least in the more industrialized
countries, average blood-lead levels have fallen to extremely low leve
ls and very few individuals can be found with blood lead levels above
currently accepted levels of concern. (C) 1998 Published by Elsevier S
cience S.A. All rights reserved.