Nairobi Air Pollution

A herd of cattle feeding beside a burning pile of garbage at Mukuru Kayaba slums, Nairobi on March 22, 2020. Air pollution is the 'new tobacco' and the simple act of breathing is killing seven million people a year and harming billions around the world.

| File | Nation Media Group

The air we breathe in Nairobi is killing us, study reveals

Did you know that dirty air is the second biggest cause of death on the continent, after non-communicable diseases (NCDs)?

Last year, the results of a 27-month study conducted in Dagoretti, Embakasi, Kamukunji, Kasarani, Langata, Makadara, Starehe and Westlands revealed that pollution levels in Kenya's capital city were 19 micrograms per cubic metre of air (µg/m3). This is relatively higher than the World Health Organisation's recommended daily standard.

Current guidelines state that the annual average concentration of particulate matter (PM) 2.5 should not exceed 5 µg/m3.  Average 24-hour exposures should not exceed 15 micrograms per cubic metre, and if they do, they should not exceed four days a year.

The study, conducted by the University of Nairobi (UoN) in collaboration with Addis Ababa University, Makerere University, University of Rwanda, Columbia University, University of Southern California and Colorado School of Public Health, said that a test conducted on schoolchildren aged 0-11 years found that at least 10 per cent had abnormal chests.

The experts went on to say that this was the main reason for the increase in hospital admissions and deaths in six hospitals as a result of household surveys of children who had undergone spirometry.

Spirometry is the most common lung function test.

It measures lung function, specifically the amount and/or speed of air that can be inhaled and exhaled, and is helpful in assessing breathing patterns that identify conditions such as asthma, pulmonary fibrosis, cystic fibrosis and chronic obstructive pulmonary disease (COPD) or chronic bronchitis.

"Females were slightly more common than males, accounting for 54.8 per cent, while males accounted for 45.2 per cent of the ten per cent of children with abnormal chests. A total of 1000 children were involved in this research," said the UoN researchers, who are part of a consortium known as the Global Environmental and Occupational Health (GEO Health) Hub for Research and Training in Eastern Africa.

The study also found that pollution levels vary from region to region and that there is a strong link between pollution levels, climate change and human activities that can be controlled, such as traffic and waste burning.

"The air we breathe is very dirty and it is killing us. As the World Health Organisation recently said, air pollution is the 'new tobacco' and the simple act of breathing is killing seven million people a year and harming billions more," said Professor Nicholas Oguge, the lead researcher from the UoN, in an interview with the Nation.

But what causes the dirty air?

"In most cases, air pollution is caused by human activities such as mining, construction, transport, industrial work, agriculture, smelting and burning of waste, but also by natural causes such as windblown dust," he said.

"Pollutants can be found in the air in two main forms, firstly as gases - such as the greenhouse gases that cause global warming - and secondly as particles suspended in the air (particulate matter). Fine particulate air pollution, also known as PM2.5 (airborne particles measuring 2.5 micrograms or less in aerodynamic diameter), is a known cause of death from cardiovascular (heart), respiratory (lung) and other diseases due to long-term exposure to air pollution," Professor Nicholas explained.

The professor goes on to explain that air pollution in Nairobi is 19 µg/m3, in Kampala 39 µg/m3 and in Addis Ababa 42 µg/m3.

"Nairobi scores slightly better than the other regions because it has green spaces such as forests and parks that help clean the air. These green spaces include the Arboretum, City Park, Karura Forest, Ngong Forest and Nairobi National Park. They absorb an amazing amount of pollutants. But even within Nairobi there are variations. The Central Business District has the highest pollution levels (35 µg/m3) and the Karen area has the lowest (10 µg/m3)," he told the Nation.

One thing that all East African cities have in common in terms of air quality is that they all peak during the morning and evening rush hours when traffic is at its peak. During this time, vehicles in traffic spew large amounts of fumes, mostly carbon, into the air.

Professor Oguge breaks down how exposure to dirty air affects people living in the EAC cities studied.

" Exposure to high levels of air pollution has been shown to cause a variety of adverse health effects, including increased risk of respiratory infections, heart disease and lung cancer, aggravation of asthma, hospital admissions and even premature death related to heart and lung disease, serious cardiovascular problems including heart disease and stroke, inflammatory effects on the heart (raising blood pressure and worsening pre-existing heart conditions), reduced lung function, and increased risk of death with long-term exposure to polluted air."

"The burden of disease from air pollution in sub-Saharan Africa is among the highest in the world, with the rate of deaths related to air pollution (155 deaths/100,000 people) much higher than the global average (85.6/100,000).

In Kenya, over 5,000 people die prematurely every year due to ambient (outdoor) air pollution," he said. 

Dr Shilpa Ranjan Mulki, a physician and diabetologist at the Lions Sightfirst Eye Hospital Diabetes Care Centre, agrees with Professor Oguge.

"While more critical evaluation is needed, several studies have shown that an increase in air pollution is significantly associated with an increase in the number of people living with diabetes. Diabetes is a disorder where chronic inflammation leads to the inability of our endogenous insulin to work properly, allowing sugar to circulate in the blood in excess amounts, leading to damage to most, if not all, organs," Dr Shilpa told the Nation.

"The result is - complications of diabetes as we know it - blindness, stroke, heart attack, chronic kidney disease, sexual dysfunction, metabolic liver disease and limb amputations to name a few."

The consultant diabetologist stresses that moderate levels of air pollution (PM 2.5) predispose people to diabetes, and believes that Nairobi is just about there.

"The number of people with diabetes is increasing. A link needs to be investigated here in our country, and policies for screening, management and early prevention are key. Air pollution triggers chronic inflammation and thus increases the risk of type 2 diabetes, diabetes in pregnancy, autoimmune diseases and other chronic diseases".

That is why she is urging the government to improve public transport regulations on carbon emissions from vehicles and factories. This, she says, will go a long way to improving air quality in the city.  

"Education is key here. Kenyans need to know the impact of these carbon emissions, even on their health. If your car is spewing that black smoke, you should know that it is not good for the environment and it is not good for your health. The health of the planet affects our health. We are all individually responsible," said Dr Shilpa.

In an interview with the Nation, Nasra Nanda, a member of the Nairobi City County Assembly and a member of the Environment and Resources Committee, agreed that poor air quality is a pressing issue in urban areas, and Nairobi is no exception.

"With its rapidly growing population and increasing number of vehicles and industries, Nairobi's air quality has continued to deteriorate, posing a serious threat to the health and well-being of its residents. The need for air quality legislation in Nairobi cannot be overemphasised," she said, explaining why the county legislators passed the Nairobi Air Quality Bill in March this year.

"These laws will serve to regulate and control air pollution, thereby protecting the health of citizens living in this vibrant city. Ideally, such laws will require industries to adopt cleaner production processes while ensuring that vehicles comply with the latest emission standards. The law will support the county's agenda for a green Nairobi and a dignified life as the effects of air pollution on human health are many," said Nasra.

Recent findings from another study by the United Nations Environment Programme (UNEP) found that air pollution was responsible for 1.1 million deaths across Africa.

UNEP found that most of these deaths - 697,000 - were the result of household air pollution, largely caused by indoor cooking stoves.

According to Boston College biology professor Philip Landrigan, who led the project with UNEP chief environmental economist Pushpam Kumar, air pollution is the second leading cause of death in the region, accounting for more deaths than tobacco, alcohol, road accidents and drug abuse, and only HIV/AIDS causes more deaths.

"Deaths attributable to air pollution result from lower respiratory infections at 336,460 deaths, ischaemic heart disease - related to blockages in the arteries - (223,930), neonatal disorders (186,541), chronic obstructive pulmonary disease (70,479) and stroke (193,936)," the report said, while also linking dirty air to far-reaching effects of reduced intellectual development in Africa's children.

The burning of fossil fuels has already led to an increase in outdoor air pollution, which killed 29.15 people per 100,000 in 2019, up from 26.13 deaths per 100,000 in 1990.