In Chile, at least 60% of the country's urban population live in cities at which ambient PM_2.5 exceeds the annual ambient air quality standard (AAQS) of 20 μg/m³. We assess the effectiveness of ambient PM_2.5 regulations in Chile by estimating meteorologically adjusted trends in ambient PM_2.5. This analysis includes 9 geographical regions, 33 monitoring sites in 23 cities, comprising 61% of Chile's urban population. We find a significant downward trend in ambient PM_2.5 in most cities that have an Air Quality Management Plan (AQMP, PDA in Spanish); these include the case of Santiago and southern cities at which ambient PM_2.5 is dominated by residential wood burning (RWB). However, in cities without AQMP our results are mixed: in some cities there is no significant trend at all and in others there is a downward, significant trend, ascribed to nationwide regulations upon mobile sources. Overall, we estimate a significant downward trend in ambient PM_2.5 for 56% of Chile's urban population. Hence, ongoing regulations have been efficient in reducing ambient PM_2.5. The significant downward trends are higher in magnitude (up to 4.4 μg/m³ per year) for smaller, more polluted cities than for cleaner or larger urban zones (down to 0.3 μg/m³ per year).

在智利，至少有60％的城市人口居住在环境PM _2.5超过年度环境空气质量标准（AAQS）20μg/ m ^3的城市。我们通过估算气象调整后的PM _2.5趋势来评估智利的PM _2.5法规的有效性。该分析包括9个地理区域，23个城市的33个监测点，占智利城市人口的61％。我们发现在大多数制定了空气质量管理计划的城市中，PM _2.5呈显着下降趋势（西班牙语为AQMP，PDA）；其中包括圣地亚哥和南部城市的环境PM _2.5主要是住宅木材燃烧（RWB）。但是，在没有AQMP的城市中，我们的结果好坏参半：在某些城市中，根本没有明显的趋势，而在另一些城市中，由于全国范围内对移动源的监管，这种趋势呈下降趋势。总体而言，我们估计智利56％的城市人口的PM _2.5呈显着下降趋势。因此，现行法规有效地降低了环境PM _2.5。的显著下降趋势在幅度更高（高达4.4微克/米³每年）为更小，更污染城市比为清洁剂或较大的城市区域（下降到0.3微克/米³每年）。