When it comes to the environment, some countries have a dirtier reputation than others. But what exactly determines which country is the filthiest? Let's take a look at the top contenders based on data from IQAir, a global air quality information and technology company.

The "world's most polluted countries" list is compiled using data on PM2.5 pollution levels, which refers to tiny particles in the air that can cause serious health problems. The higher the PM2.5 levels, the worse the air quality. Countries with high levels of PM2.5 pollution are considered the filthiest in terms of air pollution.

According to IQAir's 2019 World Air Quality Report, the top 10 filthiest countries in terms of PM2.5 pollution are:

1. Bangladesh 

2. Pakistan 

3. Mongolia 

4. Afghanistan 

5. India 

6. Indonesia 

7. Nepal 

8. United Arab Emirates 

9. Bahrain 

10. Nigeria

These countries have the highest levels of PM2.5 pollution in the world, making them the filthiest in terms of air quality. But what factors contribute to their poor air quality levels?

Several factors can contribute to high levels of air pollution in a country, including industrial activities, vehicle emissions, waste burning, and natural sources such as dust storms and wildfires. Lack of environmental regulations and enforcement can also play a role in exacerbating air pollution levels.

For example, countries like Bangladesh and Pakistan have high levels of industrial activity and a large number of outdated vehicles on the road, which contribute to their poor air quality. In countries like Mongolia and Afghanistan, dust storms and coal-burning for heating are significant sources of air pollution.

Improving air quality in these countries requires a multi-faceted approach that includes stricter emissions regulations, investing in cleaner technologies, and raising awareness about the health impacts of air pollution. By taking action to reduce air pollution levels, these countries can work towards improving the health and well-being of their citizens.

While the title of the "filthiest country" may change from year to year as air quality levels fluctuate, the countries on this list consistently rank among the most polluted in the world. By addressing the root causes of air pollution and implementing sustainable solutions, these countries can make progress towards cleaner, healthier environments for all.