Association of multi-heavy metals exposure and lung function in a typical rural cohort of Northwest China

Abstract Background Heavy metal exposure is associated with decreased lung function, but the relationship between metals co-exposure and lung function in rural areas of northwest China remains unclear. Therefore, the purpose of this study is to explore the effects of single or co-exposure of heavy metals on lung function in a rural cohort of northwest China. Methods All participants were recruited from the Dongdagou-Xinglong (DDG-XL) rural cohort of Gansu province. Urine levels of 10 common heavy metals were detected, including cobalt (Co), nickel (Ni), molybdenum (Mo), cadmium (Cd), stibium (Sb), copper (Cu), zinc (Zn), mercury (Hg), lead (Pb) and manganese (Mn). The lung function was detected by measuring percentages of predicted forced vital capacity (FVC%) and forced expiratory volume in one second (FEV1%) as well as the ratio of FEV1/FVC. We also analyzed the association between heavy metals and pulmonary ventilation dysfunction (PVD). Restricted cubic spline, logistic regression, linear regression and bayesian kernel machine regression (BKMR) were used to analyze the relationship between heavy metals exposure and lung function. Results Finally, a total of 382 participants were included in this study with the average age of 56.69 ± 7.32 years, 82.46% of them used solid fuels for heating and cooking. Logistic regression analysis showed that higher concentration of Hg, Mn, Sb and lower Mo may be risk factors for PVD. And linear regression showed that FEV1% and FVC% were negatively correlated with Sb, Hg, Mn, but positively correlated with Mo. Through BKMR model, we found the lung function decreased with the increase of heavy metals concentration. In addition, Hg and Mn made an enormous contribution to the decline of lung function. Simultaneously, subgroup analyses showed that the males, the people with BMI ≥ 24kg/m2 and used solid fuels showed a higher risk of PVD when exposed to Co, Zn and Hg. Conclusions This study found that heavy metals exposure were associated with impairment of lung function regardless of single exposure or co-exposure, particularly for Hg and Mn.