ABSTRACT

Monsoon plays a determinant role in defining the air quality of many Asian countries. Filter-based 24 h ambient PM₁₀ and PM_2.5 sampling was performed by using two paralleled medium volume air samplers during pre-and post-monsoon periods. A negligible change in PM_2.5 mass concentration from 45.77 to 44.46 µg/m³ compared to PM₁₀ from 74.34 to 142.49 µg/m³ was observed after the monsoon season. The air quality index (AQI) results showed that the air quality of the city retained from good to slightly polluted in both periods, where PM_2.5 remained as the main detrimental to air quality in 95% of the total days. The NOAA HYSPLIT model analysis and wind rose patterns showed air trajectories, especially in post-monsoon originated from relatively polluted areas transported higher PM₁₀. Meteorological attributes indicated a more conducive atmospheric condition for secondary pollution in the pre-monsoon. Evidence showed post-monsoon as a more polluted period, compared to the pre-monsoon and would pose an extra 1.07 × 10⁻³ lifetime risk to the local population. Similarly, a higher level of PM₁₀ in the post-monsoon caused 43% more premature mortality and 41% more deaths from all-cause mortality compare to the pre-monsoon period, respectively.

Implications: Pakistan is an under-developing country where pollution monitoring studies are decidedly limited. Notably, studies, concise PM_2.5 and health assessment are deficient. The present study may contribute to evaluating the air quality in special events such as monsoon and can also provide scientific and technical support for subsequent air pollution research. Moreover, the results help to develop adequate prevention and pollution control strategies and offer policy suggestions for monsoon observing countries in general and in particular, in Islamabad, Pakistan. These findings provide essential arguments in favor of educating people and raising awareness about the detrimental health effects of air pollution. Improving the quality of life of people with cardiovascular and respiratory disorders requires an immediate and substantial reduction of air pollution.

摘要

季风在确定许多亚洲国家的空气质量中起着决定性作用。在季风前后，通过使用两个平行的中等体积空气采样器进行基于过滤器的24小时环境PM ₁₀和PM _2.5采样。季风季节后，PM _2.5质量浓度从45.77降至44.46 µg / m ^3，而PM ₁₀从74.34降至142.49 µg / m ³，变化可忽略不计。空气质量指数（AQI）结果显示，在两个时期内，该城市的空气质量都保持从良好到轻微污染，其中PM _2.5在95％的总天数中仍然是空气质量的主要危害。NOAA HYSPLIT模型分析和风向玫瑰图显示了空气轨迹，尤其是在季风后风中，其源于相对污染较高的地区，其PM ₁₀含量较高。气象属性表明，季风前次级污染的大气条件更为有利。有证据表明，与季风前相比，季风后是一个污染更严重的时期，会对当地居民造成额外的1.07×10 ^-3的终生风险。同样，季风后的PM ₁₀水平较高，与季风前相比，季风造成的过早死亡分别增加43％，全因死亡率导致的死亡增加41％。

启示：巴基斯坦是一个欠发达国家，其污染监测研究绝对受到限制。值得注意的是，研究简明扼要的PM _2.5和健康评估不足。本研究可能有助于评估诸如季风等特殊事件的空气质量，也可以为随后的空气污染研究提供科学和技术支持。此外，研究结果有助于制定适当的预防和污染控制策略，并为季风观测国，特别是巴基斯坦伊斯兰堡的观测国提供政策建议。这些发现提供了必要的论据，有利于教育人们并提高人们对空气污染的有害健康影响的认识。要改善患有心血管和呼吸系统疾病的人们的生活质量，就必须立即大量减少空气污染。