我国环境空气中颗粒物达标统计要求研究

基于世界卫生组织(WHO)和美国制定颗粒物达标统计要求的原则,利用我国120个城市2005~2012年可吸入颗粒物(PM10)的实际监测数据,通过统计回归法、比例反推法和控制图法对我国不同地理区划城市的颗粒物达标统计要求进行了分析研究.结果表明,当我国城市PM10浓度达到年均值标准时,大多数城市PM10日均值的达标率均在95.0%以上,平均为97.1%;其中华北、西北地区城市的平均达标率为96.3%,东北地区城市平均达标率为96.6%,华东、中南地区城市平均达标率为97.2%,西南地区城市平均达标率为98.1%.当我国PM10达标统计要求等于97百分位数时,日均值标准和年均值标准的控制力度基本匹配,当达标统计要求高于97百分位数时,日均值标准成为控制性标准,反之年均值标准成为控制性标准.综合考虑我国城市PM10浓度统计特征、百分位数的稳健性和对人体健康的保护性等各方面因素,我国宜选择95百分位数作为我国目前的PM10和PM2.5的日均值达标统计要求.

Form of the Particulate Matter Ambient Air Standards in China

Based on the principles from the World Health Organization (WHO) and the United States, an analysis was conducted to study the form of 24-hour standard of particulate matter in China by methods of statistical regression, proportional rollback and controlling contrast maps, using the monitoring data of inhalable particulate matter (PM₁₀) from 120 cities in China during year 2005 to 2012. It was found that for cities in China, when the annual arithmetic mean of PM₁₀ was equal to the national standard, the non-exceedance rates of daily average PM₁₀ in most cities were higher than 95.0%, and the average rate for all cities was 97.1%. The average non-exceedance rate was 96.3% for cities in North China and Northwest China, 96.6% for Northeast China, 97.2% for East China and Central South China, and 98.1% for Southwest China. When the 97^th percentile was chosen as the form of 24-hour standard of particulate matter for China, the 24-hour standard had an equal controlling strength with the annual standard. The 24-hour standard will become the controlling standard when larger percentiles were chosen, otherwise the contrary. By considering together the statistical characteristics of PM₁₀ level in China, the robustness of the percentiles and protection of human health, the 95^th percentile was suitable as the preferred form of the 24-hour standard of PM₁₀ and PM_2.5 in China.