Cambodia & Environment: Questions about air pollution in Phnom Penh

Recent alarmist reports about air pollution in Phnom Penh have somewhat alarmed the public and the media, tending to present the situation in Cambodia as catastrophic. This is not entirely the case, and this is an opportunity to remind ourselves that the situation deserves to be clarified.

Phnom Penh 2025. Photo CG

Is the air in Phnom Penh really polluted?

At certain times of the year, air quality in Phnom Penh is often poor, especially during the dry season (November-April). The main pollution factors are:

• Vehicle emissions: Older vehicles, lack of emission controls and rapid urbanisation.

• Construction dust: high-rise buildings and infrastructure projects emit fine particles (PM2.5/PM10)

• Industrial pollution: Factories (e.g. brick kilns) and waste combustion

• Biomass burning: Farmers burn crop residues and waste in neighbouring provinces

• Weather conditions: Dry, stagnant air traps pollutants, which is exacerbated during seasonal agricultural burning.

The AQI (air quality index) often exceeds WHO safety limits (PM2.5 > 25 μg/m³). For example, in 2023, the annual average PM2.5 in Phnom Penh was around 35-50 μg/m³, with peaks of 150+ μg/m³ on bad days (similar to highly polluted cities such as Delhi or Bangkok).

Will this situation become permanent?

Air pollution in Phnom Penh is not necessarily permanent, but long-term solutions are needed to reverse it:

• Government action: Stricter emissions standards, environmentally friendly public transport (e.g. electric buses) and implementation of building and dust control measures

• Urban planning: reducing traffic congestion, extending green spaces and regulating industrial zones

• Regional cooperation: Tackling cross-border haze from agricultural burning in neighbouring countries

However, there is still much room for improvement. Cambodia's rapid development often prioritises economic growth over environmental protection. In the absence of systemic changes, pollution is likely to persist or worsen as the city grows.

Is this pollution dangerous?

Prolonged exposure presents health risks. In the short term, it can cause irritation of the eyes, throat and lungs, and aggravation of certain allergies.

In the long term, there is an increased risk of heart disease, lung cancer and respiratory illnesses. Vulnerable groups (children, the elderly, people with pre-existing conditions) are the most exposed. PM2.5 particles (tiny enough to penetrate the bloodstream) are the main concern. The WHO estimates that air pollution is responsible for many premature deaths each year in Cambodia.

React

• Check the AQI in real time on platforms such as IQAir or AirVisual

• Wear N95 masks outdoors on days of heavy pollution

• Use air purifiers indoors

• Avoid exercising outdoors during hours of high pollution

Outlook

Air pollution in Phnom Penh is not irreversible, but significant improvement depends on political will, public awareness and investment in sustainable infrastructure. For now, it poses a serious but manageable risk to residents and visitors. Cities such as Beijing and Mexico City have shown that pollution can be reduced through sustained efforts, but the way forward for Cambodia has yet to be defined.