Why does air pollution disproportionately affect minority ethnic groups?

Ella Kissi-Debrah was the first person in the world to have air pollution listed as the cause of death. She was just nine years old when she died.

Ella was also from a minority ethnic background, making her more likely to live in an area with poor air quality, according to numerous studies covering the UK and US.

In England, people of colour are three times more likely to live in areas with high air pollution, according to research by environmental organization Friends of the Earth. These areas have pollution levels that are double World Health Organization (WHO) standards for at least one of the two most deadly air pollutants, the study found.

These pollutants are nitrogen dioxide (NO2) and particulate matter (PM2.5), and the just over 2,500 areas found to have excess levels of these pollutants had an average minority ethnic population of 44%, according to Friends of the Earth.

This is far higher than the proportion of England’s residents who are from a minority ethnic background, which stands at 16.1%, UK newspaper The Guardian notes.

A similar study in the US by Harvard University’s public health school found that areas with above-average Black, Asian and Hispanic or Latino populations have been “consistently exposed” to higher average PM2.5 levels.

The research, published in the scientific journal Nature, combined 17 years of demographic data with figures on fine particulate pollution from across the US. “In 2016, the average PM2.5 concentration for the Black population was 13.7% higher than that of the white population,” it found.

In addition, as the Black population increased in a particular area, so did the PM2.5 concentration. And there was a “steep incline” for neighbourhoods where more than 85% of the population was Black, with a similar trend for areas with high Hispanic and Latino populations, the Harvard team noted.

So why is this happening? Some say that the current disparities in air quality in the US are linked to past discriminatory decisions, including “redlining”.

This was when authorities literally drew red lines on maps around areas with larger Black populations, to try and warn mortgage lenders away from offering loans to people in these areas. It led to a lack of investment and economic disadvantage, according to The Brookings Institution.

On top of this, minority and low-income neighbourhoods are “disproportionately targeted by industries that follow the path of least resistance when deciding where to locate hazardous waste sites and other polluting facilities,” according to the University of Michigan.

“Communities of colour, especially Black communities, have been concentrated in areas adjacent to industrial facilities and industrial zones, and that goes back decades and decades, to redlining,” Justin Onwenu, an organizer for environmental group the Sierra Club, told The New York Times. “A lot of our current infrastructure, our highways, were built on – built through – Black communities, so we’re breathing in diesel emissions and other pollution just because we’re located right next to these highways.”

Back in the UK, Ella Kissi-Debrah lived 25 metres from the busy South Circular Road in South London. The high volumes of traffic have led to nitrogen dioxide levels in the area constantly exceeding annual legal limits, The Guardian reports.

Other UK research by Greenpeace and race equality think tank the Runnymede Trust found that Black, Asian and other minority residents in cities live in “air pollution sacrifice areas”. These are places with “non-existent access to green spaces and … pollution-heavy infrastructure such as recycling centres, industrial sites and incinerators”.

The air pollutant that affects people the most is particulate matter, also known as PM, the WHO says. The number used with these PM measures represents the diameter of the particles. The lower the number, the more damage they can cause to our health.

PM2.5 means a diameter of 2.5 microns or less. “These particles are so small that 60 of them make up the width of a human hair,” the WHO says. “PM2.5 can penetrate the lung barrier and enter the blood system. They can increase the risk of heart and respiratory diseases, as well as lung cancer.”

The other most harmful air pollutant is nitrogen dioxide, which can cause asthma, reduced lung function and inflammation of our airways. It can also lead to a greater likelihood of emergency department and hospital admissions, according to the American Lung Association.

The biggest sources of NO2 are cars, trucks and buses. Power plants, diesel-powered heavy construction equipment and industrial boilers are also notable contributors.

Harvard University’s public health school says that its findings illustrate the need for strong, targeted strategies to cut air pollution. This is the only way “to move closer toward the US Environmental Protection Agency’s aim to provide all people with the same degree of protection from environmental hazards”, it says.

Friends of the Earth says the world needs to take big steps to improve air quality, including:

There are several global groups working to cut the level of pollutants in the atmosphere. These include the World Economic Forum’s Alliance for Clean Air which brings together some of the world’s biggest companies – including Google, Ikea and Siemens – to champion initiatives to reduce air pollution. The firms have also set ambitious targets to cut their own emissions.

Meanwhile, the Forum’s Global Future Council on Clean Air brings together leaders from government, business and civil society to promote an integrated approach to improving air quality based on scientific evidence and strong political action.

As Ella Kissi-Debrah’s mother puts it: “Everyone deserves a right to breathe clean air.”