The risk of imbalance in the population composition of lymphocytes and specific sensitization in children living under exposure to airborne ben-zo(a)pyrene in the arctic zone of Russia

Abstract

Climatic and geographical determinants of the Arctic zone can aggravate effects of technogenic chemical factors and induce health disorders in children even at low exposure levels. 1291 children aged 3–6 years were examined. Group A included 608 children living in an urbanized area in the Arctic zone. Group B consisted of 204 children from a conventionally clean area of the Arctic zone. Group C included 308 children from an urbanized middle latitude area. Group D consisted of 171 children from a conventionally clean middle latitude area. Benzo(a)pyrene levels in ambient air and in blood were determined by HPLC. Identification of T-(CD3+) and B-lymphocytes (CD19+) was carried out by flow cytofluorometry. Exposure to airborne benzo(a)pyrene (0.6 average daily MPL) in the Arctic zone in a daily dose equal to 7.11•10-3 µg/(kg•day) results in blood of exposed children being contaminated with benzo(a)pyrene and in lower levels of Т-lymphocytes (СD3+) (OR (CI) = 2.99 (2.00–4.46); RR (CI) = 1.94 (1.47–2.56); p = 0.024) against hyperexpression of B-lymphocytes (CD19+) (OR (CI) = 2.55 (1.83–3.56); RR (CI) = 1.68 (1.36–2.06); p = 0.019) and IgG to benzo(a)pyrene (OR (CI) = 53.33 (27.56–103.20); RR (CI) = 15.11 (8,24–27.72); p = 0.001) in comparison with children living on a conventionally clean territory (p < 0.05). Similar disorders are identified in children in case benzo(a)pyrene is introduced in a dose equal to 87.6•10-3 µg/(kg•day) under airborne exposure (7.4 average daily MPL) in the middle-latitude zone (p > 0.05). Thus, children who live in the Arctic zone and are exposed to airborne benzo(a)pyrene in an average daily dose equal to 7.11•10-3 µg/(kg•day) face an elevated risk of imbalance in the population composition of lymphocytes as per basic cell differentiation clusters (CD3+ and CD19+; RR = 1.68–1.94; p = 0.024–0.019) and specific sensitization (IgG to benzo(a)pyrene; RR = 15.11; p = 0.001). This risk is comparable with effects of exposure to airborne benzo(a)pyrene in an average daily dose equal to 87.6•10-3 µg/(kg•day) in the middle-latitude zone. These findings confirm the hypothesis on effects of technogenic chemical factors being potentiated by specific climatic and geographic conditions (low average annual temperatures and photoperiodic asymmetry). Their additive effects induce early manifestations of pathological phenotypic health disorders in children even under low levels of exposure to benzo(a)pyrene.