Exposure of Prague's homeless population to lead and cadmium, compared to Prague's general population

Homelessness is a growing problem in the Czech Republic where homeless people represent a specific minority group beset by many problems linked to their divergent lifestyle. It was therefore expected that the homeless population would be at greater risk of exposure to environmental pollutants than the general population. The aim of our study was to compare blood lead (B-Pb) and blood cadmium (B-Cd) levels in the homeless population (HP) with those obtained from the Human Biomonitoring Project (CZ-HBM), which used blood donors considered representative of the general population (GP). We present data obtained between 2004 and 2006 for B-Pb and B-Cd in 257 Prague homeless adults and compare them to B-Pb and B-Cd levels in 104 Prague adult blood donors from the CZ-HBM project in 2005. The mean (geometric) B-Pb levels in men were 36.5 (HP) and 35.4microg/l (GP), which is not significantly different. However, statistically significant differences were observed between men and women in the GP (P<0.001), but not in HP; B-Pb levels in women (34.8microg/l) did not differ from those of HP men (36.5microg/l), but were significantly (P<0.001) higher than those of GP women (25.8microg/l). B-Pb levels were not influenced by smoking. B-Cd levels in the homeless nonsmokers (geometric means 1.06 and 1.18microg/l in men and women, respectively) were more than 2.5 times higher than in the nonsmoking GP (0.36 and 0.38microg/l for men and women, respectively). B-Cd levels were significantly (P<0.001) influenced by smoking in both groups, but, surprisingly, the values in GP smokers (men=0.96microg/l, women=0.93microg/l) were lower than those in HP nonsmokers (men=1.06microg/l, women=1.18microg/l). A positive correlation was found between cadmium and lead in both men (P<0.05) and women (P<0.01). Our results indicate that the homeless population under study might be exposed to lead and cadmium more extensively than the general population of Prague and that homeless women represent a particularly vulnerable population group.