Page 1038 - Basic _ Clinical Pharmacology ( PDFDrive )

1024 SECTION IX Toxicology

Prevention of Lead Poisoning: An Ongoing Effort

Exposure: Sources Examples of Preventive Measures

Home exposure: The US Consumer Product Safety The US Environmental Protection Agency’s (EPA) Lead Renovation, Repair,
Commission adopted major restrictions on the use and Painting Rule requires that companies performing renovation, repair,
of lead in residential house paint in 1977. Prior to and painting projects that disturb lead-based paint in homes, child care
then, thousands of tons of lead pigments were facilities, and preschools built before 1978 have their firm certified by EPA
applied in millions of homes. The American Healthy (or an EPA-authorized state), use certified renovators who are trained by
Homes Survey (2005–2006) estimated that 35% of EPA-approved training providers, and follow lead-safe work practices.
homes had some lead-based paint and 22% had [https://www.epa.gov/lead/renovation-repair-and-painting-program]
one or more lead-based paint hazards.
Workplace exposure: The US Occupational Health Present OSHA rules regarding workplace lead exposure and medical
and Safety Administration (OSHA) estimates that removal protection date from the late 1970s and no longer offer adequate
more than 1.6 million workers are potentially protection. The Occupational Lead Poisoning Prevention Program of the
exposed to lead. State and federal OSHA programs California Department of Public Health offers up-to-date, health protec-
have established permissible exposure levels for tive guidance.
lead in workplace air, as well as medical surveillance [https://archive.cdph.ca.gov/programs/olppp/Pages/default.aspx]
requirements for workers that may mandate peri-
odic blood lead monitoring.
Water: Lead may enter drinking water when service Under EPA’s Lead and Copper Rule [https://www.epa.gov/dwreginfo/lead-
pipes contain lead, especially when the water has and-copper-rule], if more than 10% of tap water samples at sites likely to
high acidity or low mineral content that corrodes have lead plumbing exceed the lead action level of 15 parts per billion,
pipes and plumbing fixtures. water systems are required to institute corrosion control and other mea-
sures. The Safe Drinking Water Act, amended by the Reduction of Lead in
Drinking Water Act of 2011, sets limits on the lead content of new plumb-
ing materials for potable water.
[ https://www.epa.gov/dwstandardsregulations/
use-lead-free-pipes-fittings-fixtures-solder-and-flux-drinking-water]
Children: Because of normal mouthing behavior, The US Consumer Product Safety Commission has promulgated rules that
children are at special risk of exposure to lead limit the amount of lead that can be present in children’s products.
present in toys, jewelry, printed material, and [https://www.cpsc.gov/Business--Manufacturing/Business-Education/
other consumer products.
Lead/Lead-in-Paint]
[https://www.cpsc.gov/Business--Manufacturing/Business-Education/
Lead/Total-Lead-Content]

Production of lead began 6000 years ago, and lead poisoning is one of the oldest known occupational illnesses. Worldwide, lead produc-
tion has doubled over the past two decades in part because of the growing demand for lead acid storage batteries. Efforts to prevent lead
poisoning from multiple industrial, commercial, and environmental sources remain an active focus of public health in the USA.

that chelation treatment for lead encephalopathy be initiated with Although most clinicians support chelation for symptomatic
an intramuscular injection of dimercaprol, followed in 4 hours by patients with elevated blood lead concentrations, the decision
concurrent administration of dimercaprol and EDTA. Parenteral to chelate asymptomatic subjects is more controversial. Since
chelation is limited to 5 or fewer days, at which time oral treat- 1991, the Centers for Disease Control and Prevention (CDC)
ment with another chelator, succimer (DMSA), may be insti- has recommended chelation for all children with blood lead
tuted. In symptomatic lead intoxication without encephalopathy, concentrations of 45 mcg/dL or greater. However, a random-
treatment may sometimes be initiated with succimer. The end ized, double-blind, placebo-controlled clinical trial of succimer
point for chelation is usually resolution of symptoms or return of in children with blood lead concentrations between 25 and
the blood lead concentration to the premorbid range. In patients 44 mcg/dL found no benefit on neurocognitive function or
with chronic exposure, cessation of chelation may be followed by long-term blood lead reduction. Prophylactic use of chelating
an upward rebound in blood lead concentration as the lead re- agents in the workplace should never be a substitute for reduc-
equilibrates from bone lead stores. tion or prevention of excessive exposure.