The silent epidemic: Lead poisoning

Abstract

IT IS ESTIMATED that approximately 1,000,000 US children younger than the age of 5 years have high lead levels (Centers for Disease Control and Prevention [CDC], 2000). Lead is classified as a neurotoxin and has been shown to affect the cognitive development of children (Preston, Warren, & Wooten, 2001). Low levels of lead exposure may produce generalized symptoms such as anorexia, vomiting, abdominal pains, and headaches. Often these initial symptoms go unnoticed or may be mistaken for other illnesses. Consistent low-level lead exposure (10 mcg/dl) is associated with behavior and learning problems, delayed growth, and hearing loss. High lead levels (100 mcg/dl) have been associated with mental retardation, encephalopathy, coma, seizures, and death (Cohen, 2001; Fisher & Vessy, 1998). The effects of lead on the developing brain and nervous system are often permanent (CDC, 2000). Several attempts have been made to reduce lead exposure in the environment. The United States first began selling lead-based paint in 1923. Lead pigments were added to make the paint last longer and cling to surfaces better (Environmental Protection Agency [EPA], 1999). The sale of lead-based paint was finally banned for use in residences, on household furniture and on children’s toys in 1978 by the Consumer Product Safety Commission (CPSC). Ten years latter in 1988, Congress changed the Safe Drinking Water Act to restrict the use of lead in pipes, solder, and other components used in public, residential, and nonresidential water systems. The EPA began the phase-out of leaded gasoline in 1976 (EPA, 1999). All of these efforts, have led to a reduction in the mean blood lead level (BLL) of US children by 80% over the last 20 years (Pirkle, Brody, & Gunter, 1994). Despite these advances, lead poisoning is still classified as a “serious environment health hazard” as 4.4% of all US children ages 1 to 5 years still have elevated blood lead levels. Lowincome children are eight times at higher risk and African-American children are 5 times at higher risk for lead poisoning than other US Children (CDC, 1997). Contaminated soil, dust, and paint are the most common sources of lead exposure (Lynch, Boatright, & Moss, 2000). Nearly two thirds of all US homes still have lead-based paint (Westat, 1995). Deterioration of the paint caused by poor maintenance or remodeling projects releases lead particles. The inhalation or ingestion of these particles accounts for 5% to 10% of all poisonings (Ryan, Levy, & Pollack, 1999). Another source of lead is from water pipes. Lead found in old pipes may leech into water supplies. Other less common sources of lead include: imported foods such as tamarind products, food coloring (lozenna) from Iraq, prune juice concentrate from France, duck eggs from Taiwan, and raisins from Turkey (Lynch, Boatright, & Moss, 2000). There are variations in the recommendations for screening for blood lead levels. In some states, evidence of lead screening must be presented to the school at the time of the child’s enrollment (Markowitz, Rosen, & Clemente, 1999). Because of the increase in the incidence of lead-poisoning in low-income and AfricanAmerican children, the CDC and the American Academy of Pediatrics (APA) have revised their