Most polluted countries based on PM2.5 concentration globally 2023

Bangladesh had an average PM2.5 concentration of nearly 80 micrograms per cubic meter of air (µg/m3) in 2023, becoming the most polluted country in the world. This was over 25 µg/m³ more than the average PM2.5 concentration in India. The high levels of pollution in Bangladesh can be explained by the country's persistent traffic, construction activities, and industrial fumes – in particular from brick kilns, which are highly reliant on coal.What are PM2.5 pollutantsPM2.5 refers to fine particles that have a diameter of 2.5 micrometers or less. These tiny, light, and inhalable pollutants can stay in the air for long periods of time and are a major risk to human health when concentrations are high. The World Health Organization advises that annual mean PM2.5 concentrations should not exceed 5 µg/m³. Major sources of PM2.5 include solid waste burning, road vehicles, and power plants. Pollution in citiesIn 2023, New Delhi was the most polluted capital city in the world, with an average PM2.5 concentration of 92.7 µg/m³. This was followed by the Bangladeshi capital, Dhaka. Despite these high PM2.5 levels, the most polluted city worldwide was Begusarai – in northeastern India – with an average PM2.5 concentration of nearly 119 µg/m³.

在2023年，孟加拉国空气中PM2.5的平均浓度接近80微克每立方米（µg/m³），成为世界上污染最为严重的国家。这一数值比印度平均的PM2.5浓度高出25 µg/m³。孟加拉国污染严重的程度可归因于该国持续的交通流量、建筑活动以及工业废气（尤其是来自依赖煤炭的砖窑所产生的废气）。何谓PM2.5污染物？PM2.5指的是直径小于或等于2.5微米的细颗粒物。这些细小、轻盈且可吸入的污染物能在空气中长时间存在，当浓度较高时，对人类健康构成重大风险。世界卫生组织建议，PM2.5的年浓度平均值不应超过5 µg/m³。PM2.5的主要来源包括固体废物燃烧、道路车辆和发电厂。城市污染情况在2023年，新德里成为世界上污染最严重的首都，其空气中PM2.5的平均浓度为92.7 µg/m³，紧随其后的是孟加拉国的首都达卡。尽管这些城市的PM2.5水平较高，但全球最污染的城市是位于印度东北部的贝古萨雷，其空气中PM2.5的平均浓度接近119 µg/m³。