This is the likely result of increased health care attention children in this age range receive through immunization programs and early child health screening for growth and development. The distribution of blood lead levels over the last four years is illustrated in Table 3 . In 1997 and 1998, more children with seriously elevated blood lead levels were detected than in 1995 and 1996. Data presented in the table indicate that minority children reported tested were more likely to suffer from lead poisoning than non-minority children. The gender distribution of blood lead levels for 1998 is provided in Table 5 .
Males have higher rates of elevated blood lead levels.
The data on blood lead measurements are subject to several limitations. First, many counties have no reported tests, which suggests that many Nebraska children with lead poisoning are not being identified. Screening of young children for elevated blood lead levels is voluntary and the data contain only results from children who present themselves for screening and whose results are subsequently reported. In 1998, a high proportion of all children identified as having elevated blood lead levels in the state resided within Douglas County. This likely reflects the presence of a focused and active pediatric lead screening surveillance system sponsored by the Douglas County Health Department, the Environmental Protection Agency and the Centers for Disease Control and Prevention.