One in six of all deaths globally was caused by pollution in 2015, according to a major study.
In the UK, 8.39% of deaths - more than 50,000 people - were due to pollution, a higher proportion than in many other European countries. Only Belgium had a worse record of the western European countries in the study.
In the most severely affected countries, including India, Pakistan, China, Bangladesh, Madagascar, and Kenya, up to a quarter of all deaths were caused by pollution.
The research, published in The Lancet, says pollution claimed nine million lives in 2015 globally, with air pollution from vehicles and factories the biggest killer, accounting for 6.5 million deaths.
More than 155,000 people were killed by pollution in the US, but those deaths made up just 5.74% of the country's total.
Most pollution victims around the world died as a result of non-communicable conditions such as heart disease, stroke, lung cancer and chronic obstructive pulmonary disease (COPD), said researchers.
The Lancet Commission on Pollution and Health was a two-year project involving more than 40 international researchers looking at a snapshot of pollution effects around the world in 2015.
Scientists analysed data from the Global Burden of Disease study, a huge inquiry into the leading causes of death and illness worldwide, to come up with the findings.
Worldwide, the biggest impact from pollution was felt in regions undergoing rapid development and industrialisation.
Around 2.5 million people in India were killed by pollution in 2015 - nearly a quarter of all deaths - and 1.8 million in China.
Professor Philip Landrigan, from the Icahn School of Medicine in New York City, US, who co-led the investigation, said: "Pollution is much more than an environmental challenge - it is a profound and pervasive threat that affects many aspects of human health and well-being.
"Despite its far-reaching effects on health, the economy and the environment, pollution has been neglected in the international assistance and the global health agendas."
The biggest cause of pollution death was found to be chemicals in the air, both outside and within households. Outdoor pollution was chiefly caused by road traffic and industrial emissions while indoor air pollution resulted from the burning of wood, charcoal, dung and crop wastes.
After air pollution, the greatest hazard was contamination of water supplies and sanitation, leading to infectious disease. Unsafe water was linked to 1.8 million deaths.
Toxic chemicals and carcinogens in the workplace accounted for 800,000 deaths from conditions such as cancer and lung disease.
The Department for Environment, Food and Rural Affairs said it had put in place a £3 billion plan to "improve air quality and reduce harmful emissions".
A spokesman added: "We will also end the sale of new diesel and petrol cars by 2040, and next year we will publish a comprehensive Clean Air Strategy which will set out further steps to tackle air pollution."