Immunologic and other biological parameters as a function of smoking status and of residence in areas differing in terms of air pollution

In the industrial region of La Louvière (Belgium), healthy persons, presenting at a consultation of preventive medicine, showed differences as a function of smoking and of residence in one of four areas differing in sources of emissions, population density and green zones. Smokers had significantly (P0.05) more leukocytes l⁻¹, neutrophils l⁻¹, CD3+ lymphocytes (lys) l⁻¹, CD4+ lys l⁻¹, CD25+ lys l⁻¹, higher CD4/CD8 ratio's and higher carcino-embryonic antigen serum levels but significantly lower IgG immunoglobulin and serum carotene levels than non-smokers. Compared to persons living in the 'Peripheral area', and after correction for sex, smoking status and age, persons living in the more polluted areas showed significantly more CD3+CD56+ lys l⁻¹. Although about the same mean value for the CD4/CD8 ratio was found for the more polluted areas, a higher percentage of their residents showed a ratio that was either <1 or 2.25, significantly so for the Power Station-Landfill area. A non-significant but consistent trend towards higher lymphocyte and CD8 lys counts and higher complement C3c serum levels further suggested an association between residence in a more polluted area and immunologic features. The number of CD3+CD56+ lys l⁻¹, reported to be increased in cancer patients, showed a negative correlation with the CD4/CD8 ratio (r²=0.132, P<0.0001).