Lead - Toxicology of Metals - page 590

with lead exposure may add to the exposure (e.g., from
touching cigarettes with unwashed hands).
Some hobbies may cause lead exposure. Examples
are indoor shooting, tin-soldier moulding, ceramic
work, application of lead-containing glazes, and motor
sports involving work with the exhaust system from
cars run on leaded gasoline. These activities give expo-
sure through inhalation, but in addition, oral intake
may occur. Finally, all particulate airborne lead sooner
or later ends up in dust or soil.

for example, from private wells. In the next link of the
chain, at distribution of drinking water, it may be con-
taminated with lead from lead pipes, lead-soldered
copper pipes, lead-containing brass joints for plastic
pipes, or from other parts of the water system. In par-
ticular, acidic and soft water has the potential for dis-
solving lead from the distribution system. The level
then depends on the time during which the water
did dwell in the pipe. Thus, the lead content is often
higher in the fi rst fl ush than a later one. In the study
in Hamburg mentioned previously, it was shown that
fl ushing water before drinking it could signifi cantly
lower blood-lead levels. Moreover, in households
without tap water, intake of contaminated rainwater
may cause exposure.
Also, lead intake occurs through foods. Lead is
present in vegetables mainly as a result of deposition
from air; uptake by roots is less important (De Tem-
merman and Hoenig, 2004). Lead is further transferred
from plants to animal foods.
There is a large variation of lead exposure through
foods between countries. For example, in the United
States an average intake in adults of 3

2.4.1.3 Ingestion
In infants and small children, ingested lead objects
(e.g., fi shing sinkers, curtain weights) may cause
massive exposure, in particular if large enough
(diameter > 20 mm) not to pass the pylorus, but are
retained in the stomach, where lead is solubilized
and absorbed further downstream. An ingested lead
object may also poison an adult (Gustavsson and
Gerhardsson, 2005).
Dust (in homes as well as in streets) and soil may
contain high lead concentrations and are signifi cant
sources of children's exposure. In particular, dust in
homes painted with paint containing lead pigment,
and soil around lead-emitting industries may contain
very high lead levels (U.S. CDC, 2002; 2005; WHO,
1995). The maximum uptake in children seems to occur
around 2 years of age and is higher in the summer than
in the winter (Baghurst et al ., 1992; Yiin et al ., 2000).
The hand-to-mouth behavior of children is important
for lead intake (Lanphear et al ., 1998), and even small
babies unable to grasp objects receive much of their
lead exposure from mouthing their own fi ngers (Kranz
et al ., 2004). The solubility of the lead ingested is of
great importance for the uptake of lead (Section 2.5.1).
When comparing inhalation and ingestion intakes,
the limited uptake of lead in the gastrointestinal tract
should be borne in mind.
The lead content of drinking water may vary con-
siderably. As an illustration of the contrast, intakes of
approximately 1

g/day has been
reported (WHO, 2000b), whereas higher values have been
given for Denmark (18

µ

µ g/day) and the United Kingdom

(27 g/day; EU SCOOP, 2004). Countries in East and

Southeast Asia ranged from 7 to 32

µ

g/day in women
in the general population (Ikeda et al ., 2000). However,
because of the changes in the pollution (Section 2.4.1.6),
such fi gures may change rapidly. Children have a con-
siderably higher dietary intake of lead in relation to body
weight than adults (EU SCOOP, 2004; WHO, 2000b).
In the diet, fruits and vegetables, cereals, bakery
wares, and beverages are major sources of lead, together
supplying most of the intake (EU SCOOP, 2004).
Alcoholic beverages cause lead exposure (Grandjean
et al ., 1981). Earlier, lead acetate was used as a sweet-
ener in wines. Today, potentially lethal doses of lead
may be taken in through illegally produced alco-
hol (“moonshine”), distilled in apparatuses with
automobile radiators, containing lead solders as
condensators. High copper intakes may also occur,
depending on the composition of the cooler. Lead
intoxications caused by moonshine run the risk of
being attributed to other causes, leaving the lead
toxicity untreated (Morgan et al ., 2003). Even less
spectacular alcoholic beverages, especially wines,
may contain considerable lead concentrations, partly
because of use of lead arsenate as a fungicide in vine-
yards and contamination from containers, including
crystal decanters and glasses (Graziano and Blum,
1991). Further, intake of herbal medicine products
(ayurvedic) may cause lead exposure (Saper et al .,
2004; Sjöstrand et al., 2007).

µ

g/day or less have been reported
from Sweden (Svensson et al ., 1987), whereas a study
in Hamburg, Germany, in an area where lead pipes
are common in old plumbing systems, showed a large
variation in the lead concentration in tapwater: from
< 5

µ

g/L (Fertmann et al ., 2004). Among
the samples, a mean of 15

µ g/L up to 330 µ

g/L was found. High con-
centrations of lead in tapwater are of special concern
for bottle-fed babies when formula feeding is prepared
from the tapwater.
Of course, any lead contamination of the water res-
ervoir is of importance. Such may occur from indus-
trial discharges or highway runoff. Also, acidity may
cause an increase in the lead concentration of water,

µ