Assessing Pregnant Women's Exposure to Toxic Metals via Indoor Dust and Biological Monitoring in Urine

Abstract

This cross-sectional study investigated heavy metal concentrations in the indoor dust of pregnant women's homes in Isfahan City, Iran. It aimed to explore the relationship between metal concentrations in indoor dust and urine, as well as their correlation with the Air Quality Index (AQI) and relevant factors. A total of 80 indoor dust samples were collected from vacuum cleaners in different locations of Isfahan City over a three-month period (January to March) in 2020-2021. Additionally, 80 urine samples were obtained. Metal concentrations, including Chromium (Cr), Lead (Pb), Mercury (Hg), and Nickel (Ni), were analyzed using ICP-OES. The AQI value was derived from the maximum 8-hour daily PM2.5 levels provided by the Isfahan Department of Environment and calculated following EPA guidelines. Standard questionnaires captured information regarding residential location, house age, floor level, floor cover, smoking habits, distance living place and green spaces, use of air conditioner usage, type of window, window opening direction, and presence of houseplants. The mean concentrations of metals in indoor dust and urine samples were determined, with non-detectable levels of Hg. Significant differences in Pb concentration were observed across various living locations, house ages, and smoking habits (p-value < 0.05). Pb and Ni concentrations varied significantly based on floor levels and the direction of opening the window (p-value < 0.05). Differences were also noted in floor cover types and the presence of houseplants with respect to Cr and Pb concentrations in indoor dust (p-value < 0.05). Notably, a significant positive correlation existed between indoor dust Pb and AQI (r= 0.53, p <0.001). The high levels of Pb, Cr, and Ni in indoor dust highlight poor indoor air quality in the homes of the pregnant women studied. It is crucial to implement measures to raise awareness about the factors contributing to heavy metal pollution among communities.