Public Health and Lead Sampling Protocols for Drinking Water: A Critical Review - Global Drinking Water Management and Conservation - page 210

10.2.2 Health Effects of Lead in Blood

Fowler and Duval ( 1991 ) studied the effects of lead on kidneys and found that
short-term high-dose lead consumed from drinking water can induce nephropathy, a
condition that can result in a reduction in the organs

'

filter toxins and
protein effectively. In two earlier studies, Cullen et al. ( 1984 ) and Wildt et al.
( 1983 ) had found reduced sperm count levels in men with BLLs of up to 50

ability to

g/L.
Adverse health effects even from low BLLs have also been found. Decreased height
and delayed breast development in pubescent females have been associated with
BLLs of 3

µ

g/dL (Selevan et al. 2003 ). (Note that a deciliter (dL) is one-tenth of a
liter.) Meta analysis studies by Schwartz ( 1994 ) and Levin et al. ( 2008 ) indicated no
sound evidence of threshold effects for BLLs.
Some studies have addressed the serious risks to cognitive and intellectual
development to which children may be exposed as a result of lead levels in water.
McMichael et al. ( 1988 ) discovered reduced IQ and cognitive development index in
children with BLLs of less than 6

µ

µ g/L and have shown that newborn children with

BLLs of less than 3 g/L had higher scores in their cognitive development index

tests than those born with lead levels of over 6

µ

g/dL
in 9-year-old children have been associated with higher dropout rates and increased
criminal activities at a later age than children who had BLLs of 5

µ g/L. Moreover, BLLs of 10 µ

µ g/dL

(Needleman et al. 1990 ).
Later studies have con rmed these findings. Lanphear et al. ( 2005 ) found

intellectual de g/L, while Lanphear

et al. ( 2000 ) found an inverse relationship between mathematics and reading scores
and BLLs in children aged 6

cits for children who had BLLs less than 7.5 µ

- 16. In the same study, Lanphear et al. ( 2000 ) found

that an increase in BLL by 1 g/dL can cause a 0.7 and 1.0 point decline in mean

arithmetic and reading scores respectively. Can

µ

eld et al. ( 2003 ) found that an

µ

increase in lifetime BLLs from 1 to 10 g/dL can reduce IQ by 7.4 points, while

Lanphear et al. ( 2005 ) showed a reduction of 6.2 IQ points (with a 95 percent
confidence interval between 3.8 and 8.6) for the same BLL range as the Canfield
study; a log-linear model con rmed that IQ levels declined the most when BLLs

were less than 10 g/L and indicated a nonlinear relationship between BLLs and

IQ. Indeed, the results indicate that an increase in BLLs from 2.4 to 10

µ

g/L can be
associated with a drop in IQ by 3.9 points, while an increase in BLLs from 10 to 20
and 20 to 30

µ

g/L can be associated with a drop in IQ levels by 1.9 and 1.1 points,
respectively (Lanphear et al. 2005 ). Zahran et al. ( 2009 ) examined the effects of
BLLs on fourth grade students

µ

subject scores including mathematics, science, and
language. Regression analysis indicated student performance on a wide range of
subjects declines signi

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g/dL. Lead ingestion in the
formative years of life can have long-lasting effects later on in life. Cognition and
neurobehavioral patterns can be affected negatively as a result of even low-level
lead exposure during early childhood (Brubaker et al. 2009 ).
Lead in drinking water can account for at least 15 percent of total lead when an
individual is exposed to lead on a daily basis according to Bois et al. ( 1989 ). Health

cantly when BLLs exceed 10 µ