Assessment of air pollution in the industrial area of the Maracanau district in Ceara state, Brazil

ABSTRACT The intensification of industrial activities and the increase in vehicular emissions have contributed significantly to the increase in atmospheric pollution in urban centers. In this context, the present study aimed to monitor the air quality in the area of Maracanaú Industrial District, in the state of Ceará, an important industrial area in northeastern region of Brazil. Samples were collected during 24 h from November 2015 to April 2016 for pollutants such as total suspended (TSP) and inhalable particle materials (PM10), NO2, SO2, O3 and heavy metals (Sb, Cd, Pb, Cu, Fe, Mn, Ni, and Zn) associated with TSP and PM10. Ozone (O3) was determined by ultraviolet absorption (254 nm) and the concentration of heavy metals were estimated by atomic absorption spectroscopy. The mean values observed for the pollutant concentrations were: 51.3 μg/m3 for TSP; 46.1 μg/m3 for PM10; 8.9 μg/m3 for SO2; 8.3 μg/m3 for NO2; 38.5 μg/m3 for O3 in 8 hours and 48.4 μg/m3 for O3 in 1 hour. Among metals, Fe (14.9 µg/m3) was the most abundant species in both particulates. All the parameters analyzed are in accordance with the values established by the Brazilian legislation and only PM10 are above the recommended by the World Health Organization in 16.7 % of the samples (mean 74.5 μg/m3). In general, the air quality in the industrial area under study can be considered good, according to the estimates of the air quality index (AQI) recommended by the US Environmental Protection Agency.

摘要：工业活动加剧与机动车尾气排放增加，显著推高了城市中心的大气污染水平。在此背景下，本研究针对巴西东北部重要工业区——塞阿拉州马拉卡纳乌工业区开展空气质量监测工作。研究于2015年11月至2016年4月期间进行24小时采样，采集了总悬浮颗粒物（total suspended, TSP）、可吸入颗粒物（PM10）、二氧化氮（NO2）、二氧化硫（SO2）、臭氧（O3），以及与TSP和PM10结合的重金属（锑Sb、镉Cd、铅Pb、铜Cu、铁Fe、锰Mn、镍Ni、锌Zn）等污染物样本。臭氧（O3）采用紫外吸收法（254 nm）进行测定，重金属浓度则通过原子吸收光谱法完成定量分析。观测得到的污染物浓度均值如下：总悬浮颗粒物（TSP）为51.3 μg/m³；可吸入颗粒物（PM10）为46.1 μg/m³；二氧化硫（SO2）为8.9 μg/m³；二氧化氮（NO2）为8.3 μg/m³；8小时平均臭氧（O3）浓度为38.5 μg/m³，1小时平均臭氧浓度为48.4 μg/m³。在各类重金属中，铁（Fe，14.9 μg/m³）是两种颗粒物中含量最高的组分。所有分析参数均符合巴西相关法规标准，仅16.7%的采样样本中可吸入颗粒物（PM10）浓度超出世界卫生组织（World Health Organization, WHO）的推荐限值，该类样本的PM10平均浓度为74.5 μg/m³。总体而言，依据美国环境保护署（US Environmental Protection Agency, EPA）推荐的空气质量指数（Air Quality Index, AQI）评估标准，本次研究涉及的工业区空气质量可判定为良好。