Environmental Engineering Reference
In-Depth Information
clothing in the apartments; worker protection, including proper respirator
and clothing; complete dust removal and collection using a vacuum with a
high-efficiency particle air filter; and proper disposal of the dust and debris,
all in accordance with building code, the Department of Housing and Urban
Development (HUD), the EPA, and related regulations. The effectiveness of dust
removal and cleanup should be determined by surface sampling (floors, walls,
window sills) before and after paint removal. Encapsulating the lead-based paint
may be a preferred and acceptable alternative to removal if approved by the
regulatory agency. Easily accessible locations, such as window sills, should be
given priority.
Lead was banned from housepaint in 1978. Food canners stopped using lead
solder in the manufacture of tin cans in 1991, and lead in gasoline was phased out
in 1995. Thus the number of children with potentially harmful levels of lead in
the blood ( > 10 µ g/dl) has dropped by 85 percent in the last 20 years. However,
there are still many older homes with lead paint, which has further deteriorated
and presents a great risk to children and adults who live in or near those homes.
Lead is still in the soil, especially near major freeways and highways, at some
worksites, and occasionally in drinking water, ceramics, and a number of other
products.
Children two to three years old absorb 30 to 75 percent of their lead from
ingesting substances, as compared to 11 percent for adults. 68 Adults excrete up
to 95 percent of ingested lead, whereas children may absorb half of it. Other
sources of lead are lead fumes and ashes produced in battery repair and burning
lead battery casings, inadequately ventilated indoor firing ranges, emissions from
industrial processes, soft corrosive water standing and flowing in lead pipe, pipe
with lead-soldered joints, some bronze and brass faucets, and chrome-plated fix-
tures; natural or added lead in food and drink; lead in dust and soil; making lead
type; handling lead scrap; lead in lead arsenate pesticides; radiator repair; pottery
and ceramics manufacture; lead crystal decanters; lead-soldered cans; colored
newsprint; household dust in urban areas; and lead in some household products,
all of which contribute to the body burden.
On one hand, the phasing out of tetraethyl lead from gasoline has introduced a
potential and unknown problem associated with manganese compounds used as a
replacement for lead, which are emitted at low levels in various forms, including
the toxic manganese tetroxide. On the other hand, a HUD study between 1970 and
1976 in New York City showed a drop in blood lead levels in children from 30
to 21 µ g/100 ml (same as 30 - 21 µ g/dl) of blood. The drop paralleled a recorded
decrease of lead in the ambient air, suggesting a significant relationship. 69 A
report from the National Center for Health Statistics found that 90 percent of
all lead in the air came from leaded gasoline and that the blood lead level of
the average U.S. resident between 1976 and 1980 dropped 38 percent, from
14.9to9.2 µ g/100 ml, and continued through 1986. 70 This drop in blood lead
level reinforces previous findings and the relationship to greater use of unleaded
gasoline.
Search WWH ::




Custom Search