A GSTM1-null variant modifies blood concentrations of cadmium, aluminum, and lead in chronically exposed adults near a steel company.

The influence of the GSTM1-null genetic variant on blood concentrations of cadmium (Cd), aluminum (Al), and lead (Pb) was examined in 460 adults living near a steel company in Santa Cruz, Rio de Janeiro, Brazil. A cross-sectional study design was used; blood metallic chemical element (MCE) concentrations were quantified using quadrupole inductively coupled plasma‒mass spectrometry; and GSTM1 genotyping was conducted via PCR. MCE exposure levels were categorized into percentiles (P25, P75, >P75) on the basis of factor analysis-derived loadings. Multinomial logistic regression analysis was performed to evaluate gene‒environment interactions with adjustments for confounders such as age, sex, alcohol consumption, and tobacco use. The GSTM1-null variant, observed in 59.3% of participants, significantly modified the effects of age (ORP75 = 1.98; OR>P75 = 2.88), sex (ORP75 = 3.61; OR>P75 = 6.77), alcohol consumption (ORP75 = 2.42; OR>P75 = 5.48), and smoking (OR>P75 = 2.85) on blood MCE concentrations. A notable interaction was detected between residential proximity to the steel company and the presence of the GSTM1-null variant (ORadjustedP75 = 2.37); the interaction was independent of age, sex, alcohol intake, and smoking history. These results suggest that the GSTM1-null variant increases susceptibility to Cd, Al, and Pb accumulation and interacts with environmental factors, exacerbating exposure risks in populations near industrial sites. These findings emphasize the importance of genetic factors in modulating the bioaccumulation of MCEs, thereby highlighting the need for genetic screening in environmental health risk assessments. Such screenings could identify at-risk individuals in industrial regions, enabling targeted public health interventions to mitigate exposure risks. Integrating genetic and environmental data can expand the understanding of MCE toxicity and guide the development of strategies to protect vulnerable populations, particularly those living near steel companies, where chronic low-level exposure to Cd, Al, and Pb poses significant health concerns.