Blood lead levels in urban children of Katowice Voivodship, Poland: results of the population-based biomonitoring and surveillance program.

The paper presents the results of the large-scale blood lead levels survey in pre-school urban children living in industrial area of Poland (Katowice Voivodship, Upper Silesian Industrial Zone-USIZ). The program, established in 1993, involves education, screening and medical care of case-children, as its major elements. Until December 1995 six thousand nine hundred sixty nine children aged 2-6 years have been examined in three towns (Chorzów, Kalowice, Sosnowiec). Geometric mean value of blood lead level (PbB) was slightly but not statistically significantly larger in boys (6.68 +/- 1.51 micrograms/dl) than in girls (6.58 +/- 1.54 micrograms/dl). In a multiple regression analysis the following variables explained variation in PbB: town (p = 0.0001), age (p = 0.005), floor on which apartment was located (p = 0.0001), number of siblings (p = 0.0001), apartment quality (p = 0.0001), carpet in a child's room (p = 0.0001), consumption of locally grown vegetables (p = 0.007), frequent trips outside the region (p = 0.0001). The results were verified with PbB as dichotomous variable. The occurrence of PbB above 10 micrograms/dl (frequency, 14.2%-17.2%) was associated with floor on which apartment was located, number of siblings, apartment's quality, the presence of carpet in child's room and frequent trips outside the region. The occurrence of PbB above 15 micrograms/dl (frequency: 2.5%-4.2% of children) was associated with the same variables and additionally, with the place of residence and intensity of vehicle traffic. The findings yield reliable population-based estimates of the risk of over-exposure of "non-hot-spot" urban children to environmental lead and highlight the important role of factors that could be classified as environmental and socio-economical determinants of blood lead level. Among environmental factors deposits of lead are still a problem in a densely populated industrial center of USIZ and the use of leaded gasoline adds to the magnitude of exposure.