This study was aimed to describe the chemical traces of air pollution in blood of residents and evaluate the association between ambient pollution and its dose absorbed internally by a human body.

The national Magen David Adom Blood Services blood donation collection platform and the National Public Health Laboratory's testing services were utilized to conduct a human biomonitoring study among blood donors in Israel. The donors' residential addresses and donations sites' locations were geocoded and merged with the levels of pollutants recorded by the nearby monitoring stations. Pollutants included nitrogen dioxide (NO₂), sulfate dioxide (SO₂), ozone (O₃), carbon monoxide (CO) and particulate matter of size <10 and 2.5 μm in diameter (PM₁₀ & PM_2.5). Metal concentrations were statistically analyzed by ratio t-test and a lognormal regression, and adjusted to age, gender and smoking (defined based on Cadmium values).

The findings indicate an independent positive association between pollutants and metals' concentrations in blood. Specifically, an increase in interquartile range (IQR) of NO₂ was associated with 9.5 % increase in As in blood. The increase in one IQR of PM₁₀ and SO₂ was associated with an increase in Pb, of 16.6 % and 12.4 %, respectively. SO₂ was also adversely associated with Cd concentrations, by increasing its levels by 5.7 %. The donors' proximity to quarries was related to the Pb blood levels higher 1.47 times compared to donors without quarries close to their residence (p-value = 0.013).

To conclude, ambient pollution levels are associated with internal metals' concentrations, reaffirming the link between the two in the pathological pathway from air pollution to morbidity.