[Lead pollution and hematologic effects in the city of La Spezia]

During 1998-1999 a survey assessed the health impact of living in an area (Zona D) of the city of La Spezia (Liguria Region, Italy) characterised by industrial plants, urban waste disposal sites and incinerators, a coal-fired power-station and a heavily trafficked thoroughfare. One of the main results was an excess prevalence and incidence of self-reported anaemia among residents in area D compared to those of the control area (Zone C). Given the environmental lead pollution in Zone D due to the emissions of a lead processing plant active since 1930, and in order to confirm the validity of previous findings, was investieable the association between residence and blood lead levels, as well as the relationship between the latter and an anaemia-specific biomarker. We re-analysed personal, occupational and haematological data of 785 residents of La Spezia Province collected by the Liguria Environmental Protection Agency (ARPAL) during 1992 as part of a biological monitoring survey of the general population about the risk of lead intoxication. Subjects were geo-referenced by the 1992 residence address, and the haematocrit value was used as the anaemia-specific biomarker. Multiple regression analysis estimated the effect of residence on log-transformed lead blood levels, and to assess the relationship between the latter and haematocrit values. After adjusting for several potential confounding factors, residents from Zone D showed a 14% increase (95% IC = 6%-23%) in the blood lead median value estimated via the log-normal regression model compared to people living elsewhere. The excess became 27% (95% IC = 14%-41%) after 30 years of residence in the study area. Similar results were obtained by focusing analyses on students (n = 89, < 18 years, non-smokers, non-drinkers). The same modelling highlighted a significant non-linear (parabolic) dose-response relationship between lead blood and haematocrit values. This trend is consistent with the findings of other Authors and might reveal an adverse haematological effect of lead values over 170, 0 microgram/l. In conclusion, The results of this investigation strengthen the epidemiological evidence of the 1998-1999 survey.