Effect of ambient air PM-bound heavy metals on blood metal(loid)s and children's asthma and allergy pro-inflammatory (IgE, IL-4 and IL-13) biomarkers.

Background: We investigated the concentrations of metals in fine particulate matter PM in the outdoor air around the home sites of 123 male children from Ahvaz, average age 7.56, along with their blood samples to measure pro-inflammatory responses (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13).

Methods: We measured 6 metals (As, Cd, Cr, Hg, Ni and Pb) in three Ahvaz's regions including industrial (Padad), vehicle traffic (Golestan) and control (Kianpars).

Results: The higher concentrations of metals in the Padad as the industrial ambient air i.e., arsenic, cadmium, chromium, mercury and nickel coincided with the higher concentrations of those metals in exposed children (P < 0.05) versus the controls. Children in Golestan, the high traffic air pollution area had the highest lead concentrations (p < 0.05). Also a significant association was shown in Padad between blood arsenic and IgE (β = 26.59, P < 0.001), IL-4 (β = 172.1, P < 0.001) and IL-13 (β = 14.84, P < 0.001), blood chromium and IgE (β = 10.38, P < 0.001), IL-4 (β = 75.27, P < 0.001) and IL-13 (β = 5.27, P < 0.001) and blood mercury and IgE (β = 13.11, P < 0.001), IL-4 (β = 108.09, P < 0.001) and IL-13 (β = 7.96, P < 0.001) and blood lead and IgE(β = 0.92, P = 0.025), IL-4(β = 7.16, P < 0.001) and IL-13(β = 0.58, P = 0.003). However, no significant relation was found for Cadmium, Nickel in blood with IgE, IL-4 and IL-13 levels. Moreover, children from industrial areas showed significantly higher concentrations of IgE (mean = 146.44 pg/200landa, P < 0.001), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 52.93 pg/200landa, P < 0.001) versus Golestan and Kianpars.

Conclusion: Children residing in an industrial area with high concentrations of metals in PM had high metals in blood and high production of IgE, IL-4 and IL-13, reflecting an immune dysregulation and brisk inflammatory responses.