Exposure analysis and human health risk of Di(2-ethylhexyl) phthalate (DEHP) across Southwest Nigerian Universities

Di(2-ethylhexyl) phthalate (DEHP), a carcinogenic compound commonly associated with airborne particulates in indoor aerosols, constituents a serious health hazard. In university environments, where air conditioning (AC) systems are widely used, DEHP and other pollutants can accumulate in AC filters and get recirculated during operation, thereby increasing the exposure levels. Therefore, aerosol samples were collected from the AC air filters to assess indoor air quality and evaluate DEHP exposure among students and staff in various micro-environments (143 spaces) across nine universities in southwestern Nigeria. The highest DEHP concentrations, 40.32 μg/g and 38.95 μg/g, were recorded in the office spaces from two different nearby universities, reflecting the influence of human activity and indoor sources. Newer buildings exhibited elevated DEHP levels, likely due to emissions from construction and furnishing materials. Medical centers with better ventilation showed the lowest concentrations, revealing the importance of air exchange in contaminant reduction. Statistical analysis revealed strong correlations between DEHP concentrations in offices and laboratories. Additionally, cancer risk assessments revealed higher values in densely populated environments. Among the different exposure routes, the hazard quotient for dermal absorption indicated the highest risk.