Lead poisoning epidemiology and demographics
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aksiniya Stevasarova, M.D.
Overview
Lead constitutes 0.002% of the Earth’s crust, and in nature it exists mainly as lead sulphide. Lead has become widely distributed in the biosphere only in the past few thousand years, almost entirely as the result of human activity (National Research Council, 1972). Once lead is introduced into the environment, it persists. The average person has less than 10 micrograms per deciliter, or 100 parts per billion, ppb, of lead in their blood. People who have been exposed to an unusual amount of lead will have blood lead levels higher than 200 ppb—most clinical symptoms of lead poisoning begin at around 100 ppb. The effect on children's mental/cognitive abilities has been noted at very low levels.[1]
Epidemiology and Demographics
Incidence
- The incidence of lead poisoning is approximately one in 38 U.S. children in the United States.
- Low income people often live in rental housing with lead paint, and unless the landlord conducts regular inspections, paint may begin to peel and residents will be exposed to high levels of lead paint dust, thus greatly increasing their chance of lead poisoning.
Prevalence
- The prevalence of lead poisoning in children, according to the CDC, in the United States is estimated to be approximately half million children ages 1-5 with blood lead levels above 5 micrograms per deciliter (µg/dL). The percentage of children in the same age group with blood lead levels greater than or equal to 10 µg/dl has declined from 77.8% in the late 1970s to 4.4% in the early 1990s, and the average lead level of a child in the United States has declined to 1.9 µg/dl between 1999 and 2002.
- Today at least 4 million households have children living in them that are being exposed to high levels of lead.
- In 1978 there were 13.5 million children in the United States with elevated blood lead levels (i.e., 10µg/dl). By 2002, that number had dropped to 310,000 children.[2] The U.S. incurs $43.4 billion annually in the costs of all pediatric environmental disease, with childhood lead poisoning alone accounting for the vast majority of it.[3]
Case-fatality rate/Mortality rate
- The case-fatality rate of lead poisoning is approximately 400,000 U.S. deaths per year.
Age
- Patients of all age groups may develop [[lead poisoning].
- The incidence of lead poisoning is higher in children; the median age at diagnosis is 1-5 years.
- Lead poisoning commonly affects individuals younger than 10 years of age.
- Chronic lead poisoning is usually first diagnosed adults.
- Acute lead poisoning commonly affects children.
- Children
Lead-contaminated household dust is the major source of lead exposure to children in the U.S.[4] A 2006 study in New York City found lead levels in settled outdoor dust, which is a source of household dust, of 175 to 730 μg/ft2, and noted that these levels exceed the HUD/EPA lead in indoor dust standard of 40 μg/ft2.[5]
- Adults
Although children are at greater risk from lead exposure, adult exposures can also result in harmful health effects. Most adult exposures are occupational and occur in lead-related industries such as lead smelting, refining, and manufacturing industries. One frequent source of lead exposure to adults is home renovation that involves scraping, remodeling, or otherwise disturbing lead-based paint. Adults can also be exposed during certain hobbies and activities where lead is used. Workers may inhale lead dust and lead oxide fumes, as well as eat, drink, and smoke in or near contaminated areas, thereby increasing their probability of lead ingestion. Between 0.5 and 1.5 million US workers are exposed to lead in the workplace (ATSDR, 1999). Other than the developmental effects unique to young children, the health effects experienced by adults from adult exposures are similar to those experienced by children, although the thresholds are generally higher.[6]
Race
- There is no racial predilection to lead poisoning.
- Lead poisoning usually affects many people through household products, workplace, and lead paint, studies show that people of color and recent immigrants are at a much greater risk for high levels of exposure than whites [7].
Gender
- Lead poisoning affects men and women equally.
Region
- The majority of lead poisoning cases are reported in the developing countries.
Developed Countries
- According to the CDC and WHO in the United States, the phasing-out of leaded petrol between 1976 and 1995 was associated with a more than 90% reduction in mean blood lead concentration. Similar effects were recorded in western Europe, Australia, Canada, New Zealand and South Africa (von Schirnding & Fuggle, 1996; Landrigan, 2002). In a number of rapidly industrializing countries, too, including China, El Salvador, India, Mexico and Thailand, declines in blood lead levels have followed the removal of lead from petrol (OECD, 1999; Mathee et al., 2006; He, Wang & Zhang, 2009). Worldwide, unleaded petrol now accounts for an estimated 99% of total sales. T
Developing Countries
- According to the CDC and WHO by the late 2010, almost all countries have phased out leaded petrol, leaving 9 countries with leaded petrol. Three countries are using only leaded petrol (North Korea, Myanmar, Afganistan), and 6 countries (Algeria, Iraq, Montenegro, Serbia, Yemen, Bosnia-Herzegovina) are using both leaded and unleaded petrol.
References
- ↑ Lanphear, Hornung; et al. "Low Level Environmental Lead Exposure And Children's Intellectual Function: an International Pooled Analysis" (PDF). Children's Health. Retrieved 2007-09-09.
- ↑ "Lead in Paint, Dust, and Soil". United States Environmental Protection Agency. Retrieved 2007-09-09.
- ↑ "Lead Toxicity: Where Is Lead Found?". United States Center for Disease Control. 2002. Retrieved 2007-09-09.
- ↑ "Lead Toxicity: Who Is at Risk of Lead Exposure?". United States Center for Disease Control. 2002. Retrieved 2007-09-09.
- ↑ Caravanos J, Weiss AL, Blaise MJ, Jaeger RJ (2006). "A survey of spatially distributed exterior dust lead loadings in New York City". Environmental Research. 100 (2): 165&ndash, 172. doi:10.1016/j.envres.2005.05.001. Unknown parameter
|month=ignored (help) - ↑ "Lead Toxicity: Who Is at Risk of Lead Exposure?". United States Center for Disease Control. Retrieved 2007-09-09.
- ↑ www.leadsafekids.org