Associations Between Personal Exposure To PM_2.5 And Kidney Function Among Children And Adults In Panel Studies

Objective:The evidence of the effect of short-term exposure to PM_2.5 on renal function is limited.Previous studies had mainly focused on the association between long-term PM_2.5 and renal function among middle-aged and old people using cross-sectional or cohort studies.The levels of PM_2.5 measured in air-monitoring station could not identify nearby sources and detect temporal changes on a time scale of a few minutes.To our knowledge,no study investigated the effect of short-term PM_2.5 exposure on renal function of children.Therefore,we aimed to evaluate the potential associations between short-term PM_2.5 exposure and renal function in children and adults.Methods:We recruited 137 children and 143 adults in Wuhan,China from July2017 to May 2018.PM_2.5 monitoring and health examinations were conducted three times in summer,autumn and winter.We measured PM_2.5 concentrations for 72 hours using personal monitor and completed questionnaire investigations before health examinations on the fourth day.After excluding the missing subjects and covariates,we applied the linear mixed-effects model to assess the associations of personal PM_2.5 exposure at different lag times and renal function indicators.Results:PM_2.5 exposure was positively associated with creatinine and urea nitrogen,and negatively associated with estimated glomerular filtration rate（eGFR）in children.During the three-day lag period,a 10μg/m³ increase in personal PM_2.5 exposure was associated with increases of 0.701%-1.215%in creatinine,and 0.678%-1.213%decreases in eGFR.The increments in urea nitrogen were 1.233%and 0.798%per 10μg/m³ increase in personal PM_2.5.5 exposure respectively,over lag0-1 days.The stratification results indicated that the effects of personal PM_2.5 exposure on creatinine and eGFR were stronger in children aged 4-6 years,boys and children who lived within 300 m from the main road.In the two-pollutant model,there was still statistical significance in the effects of PM_2.5 personal exposure on renal function indicators after adjusting SO₂,NO₂,O₃ and CO separately.However,there were no significant short-term associations between individual PM_2.5exposure and renal function indicators in adults at all lag periods.In stratified analyses,a10μg/m³ increases in the three-day lag period PM_2.5 exposure was associated with1.002%-1.590%increases in urea nitrogen in hypertensive subjects.Conclusions:Short-term PM_2.5 exposure negatively affected the renal function of children,and the effects were stronger in children aged 4-6 years,boys and those who lived within 300m from the main road.We also found the association between short-term PM_2.5 exposure and increased urea nitrogen among hypertensive adults.Our results provide preliminary evidence that children and hypertensive subjects may be more susceptive to PM_2.5 caused renal function decline.