DIFFERENT RESPONSE TO EXPOSURE TO AIR POLLUTANTS IN GIRLS AND BOYS

ABSTRACT Objective: Identify the association between exposure to fine particulate matter and hospitalizations due to respiratory diseases in children up to ten years of age in the city of Cuiabá, Mato Grosso, stratifying the analysis by sex and calculating excess costs. Methods: Ecological study of time series. The dependent variable was daily hospitalizations according to the 10th Revision of the International Classification of Diseases (ICD10): J04.0, J12.0 to J18.9, J20.0 to J21.9 and J45.0 to J45.0. The independent variables were the concentration of fine particulate, estimated by a mathematical model, temperature and relative air humidity, controlled by short and long-term trends. Generalized additive model of Poisson regression was used. Relative risks, proportional attributable risk (PAR) and excess hospitalizations and their respective costs by the population attributable fraction (PAF) were calculated. Results: 1,165 children were hospitalized, 640 males and 525 females. The mean concentration, estimated by the mathematical model, was 15.1±2.9 mcg/m3 for PM2.5. For boys, there was no significant association; for girls a relative risk of up to 1.04 of daily hospitalizations due to respiratory diseases was observed for exposure to PM 2.5 in lags 1, 2 and 6. Increase of 5 µg/m3 in these concentrations increased the percentage of the risk in 18%; with an excess 95 hospital admissions and with excess expenses in the order of US$ 35 thousand. Conclusions: Significant effect in daily hospitalizations due to respiratory diseases related to exposure to fine particulate matter was noted for girls, suggesting the need for stratification by sex in further studies.

摘要
研究目的：探究马托格罗索州库亚巴市10岁以下儿童细颗粒物（fine particulate matter, PM2.5）暴露与呼吸系统疾病住院的关联，按性别分层开展分析，并计算超额住院相关成本。
研究方法：本研究为时间序列生态学研究。因变量为依据国际疾病分类第10版（International Classification of Diseases 10th Revision, ICD-10）编码J04.0、J12.0~J18.9、J20.0~J21.9及J45.0~J45.0划分的每日呼吸系统疾病住院人次。自变量为通过数学模型估算的PM2.5浓度、气温与空气相对湿度，并通过短期及长期趋势进行混杂控制。本研究采用泊松回归广义可加模型开展分析，计算相对风险、比例归因危险度（PAR）、超额住院人次，以及基于人群归因分数（PAF）的超额医疗成本。
研究结果：本研究共纳入1165例住院儿童，其中男性640例，女性525例。经数学模型估算，PM2.5平均浓度为15.1±2.9 μg/m³。男性群体未观察到显著关联；女性群体在滞后1、2及6期的PM2.5暴露下，呼吸系统疾病每日住院相对风险最高达1.04。当PM2.5浓度每升高5 μg/m³时，该群体住院风险升高18%，对应超额住院人次达95例，超额医疗成本约3.5万美元。
研究结论：本研究发现细颗粒物暴露与女性儿童呼吸系统疾病每日住院人次存在显著关联，提示后续相关研究需按性别进行分层分析。