Environmental Engineering Reference
In-Depth Information
policy errors have been made in Europe and in Canada in adopting sampling
protocols that are not consistent with the scienti
c best practice. The chapter is
organized as follows. Section
10.2
reviews a select set of research on blood lead
levels (BLLs) and their potential health effects, including the associated social
costs. Section
10.3
reviews the nonbinding Canadian Federal Guidelines and the
very different lead sampling protocol adopted in Ontario, Canada. Section
10.4
is a
critique of the European report that is the basis of the European lead sampling
protocol; it is shown that the 30 min sampling protocol used in Europe (and in
Ontario) is not supported by the report on the scienti
c work carried out in Europe
by van Hoven et al. (
1999
) for the European Commission; it is also inconsistent
with the science of lead leaching into water. Section
10.5
restates the protocol
adopted by the USEPA, which we believe is consistent with science. Some policy
lessons are presented in the conclusion.
10.2 Adverse Health Risks and Social Costs Associated
with Lead in Drinking Water
There is a large literature on the evidence of lead in blood as a result of lead found
in drinking water. In this section, we review work published since the early 1980s
in North America and Europe, dealing with exposure to lead from drinking water
and from other sources. We organize this review into three subsections: one on the
amount of lead found in blood samples, the second on the adverse health effects of
lead in blood, and the third on the social costs associated with these adverse health
effects.
10.2.1 Amount of Lead in Blood
The health risks associated with exposure to lead are well documented, having been
the subject of many studies over a long period. Early studies showed a reduction in
blood lead levels can result from the hardening of soft water supplies (Gallacher
et al.
1983
), and increasing water pH level as well as replacing lead pipes (Sherlock
et al.
1984
). The removal of lead pipes can result in a decline in the median BLL
from 26 to 13
g/100 ml, while the reduction in plumbosolvency by raising pH can
result in a decline of median blood lead from 21 to 13
µ
µ
g/100 ml (Sherlock et al.
1984
). Elwood et al. (
1984
) also found a signi
cant contribution to BLLs from
drinking water. Thus almost all the lead in drinking water results from the use of
lead pipes and lead
fixtures and meters, which also contain lead. Although new
buildings are required to use
“
lead free
”
pipes, lead in drinking water continues to
be a problem in many regions.
“
Lead free
”
pipes according to the USEPA mean that
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