Page 82 - Encyclopedia of Nursing Research

CHILD–LEAD EXPoSURE EFFECTS n 49

neurobehavioral processes including learn- Lanphear, 2009). Until recently, lead exposure
ing disabilities, intellectual impairment, and was thought to be a problem only for poor
antisocial behavior. Researchers have dem- inner city minority populations, and parent- C
onstrated that some of these effects may be ing practices were thought to contribute to the
seen in children with BLL as low as 3 μg/dl problem. Also, many considered the elimina-
(Bellinger, 2004; Canfield et al., 2003; Chiodo, tion of lead in gasoline and paint sufficient to
Jacobson, & Jacobson, 2004; Lanphear, 2005; eradicate the problem of lead poisoning. The
Lanphear, Deitrich, Auinger, & Cox, 2000; CDC, in 1991, issued comprehensive guide-
needleman & Landrigan, 2004). lines for preventing and treating the problem
Direct results of primary and second- of childhood lead exposure. These guide-
ary efforts at prevention of lead toxicity have lines were issued after the CDC accumulated
significantly reduced BLL among young U.S. large amounts of scientific evidence from
children within the last 30 years. The major animal and human studies that supported
sources of environmental lead exposure have the hypothesis that the deleterious effects
been greatly decreased through the elim- of lead exposure occur at levels previously
ination of lead in gasoline, the banning of thought to be harmless. The guidelines were
lead-based paint for residential use, and the updated in 2005 and emphasize the need for
elimination of lead solder from food and effective strategies to eliminate environmen-
beverage cans. Despite the success of these tal lead hazards. Despite warnings about the
efforts, lead poisoning continues to occur in known hazards of lead exposure, no policy
approximately 5% of children 5 years of age for universal screening of BLLs for infants,
and younger, and much higher levels of lead children, adolescents, and pregnant women
poisoning have consistently been documen- has been established.
ted among low-income, urban, minority, and Childhood lead poisoning was first
immigrant woman and children (olympio, described in the late 1800s by Gibson, Love,
Goncalves, Gunther, & Bechara, 2009). Hardie, Bancroft, and Turner (1892), who
Although few nurse researchers have encountered a case of peripheral paralysis
investigated the effects of low-level lead expo- in a young child and described the similar-
sure on the neurobehavioral development of ities of the case to that of chronic lead poi-
children, low-level lead exposure certainly soning in adults. Gibson speculated that the
falls within the realm of the phenomena of source of the lead poisoning was paint, and
concern to the discipline. Lead exposure he described the long-lasting effects of the
is unquestionably of clinical significance; exposure. Unfortunately, most of Gibson’s
until all lead is abated from the environ- observations were ignored, as the prevailing
ment, clinicians will be faced with screen- view of the time was that once a child sur-
ing children for lead exposure, preventing vived lead poisoning, there were no lasting
exposure through educational efforts, and effects. It was not until the early 1970s that
treating the effects of this preventable pub- cross-sectional and longitudinal studies of
lic health problem. The deleterious effects of low-level lead exposure were conducted.
lead exposure have been known for a hun- These early studies of lead exposure
dred years; however, progress in prevention involved comparisons of a lead-exposed
has been slow. Some of the reasons for this group and a comparison group on intelligence
are related to society’s indifference to prob- test measures. As knowledge accumulated
lems of poor and vulnerable populations and and research strategies became more sophisti-
a lack of household educational and environ- cated, researchers began to assess the influence
mental interventions that have demonstrated of covariates, such as parental intelligence,
effectiveness at reducing BLLs in children socioeconomic status, and parental education
(Yeoh, Woolfenden, Wheeler, Alperstein, & level (Gatsonis & needleman, 1992). Although