1 in 8 deaths globally are the result of air pollution exposure

June 19, 2016

For years, scientists have been successful in associating air pollution and vehicle-related emissions with overall mortality, cardiovascular mortality, and cardiovascular disease, to name a few. They have even been able to calculate mortality figures linked to air pollution.  In February, the Global Burden of Diseases, Injuries, and Risk Factors Study, the most comprehensive international effort to measure epidemiological trends worldwide, calculated that about 5.5 million people prematurely died in 2013 because of indoor and outdoor air pollution. And before that, in September of 2015, another study found that outdoor air pollution kills 3.3 million people worldwide, a number set to double in the next 35 years if emissions continue unabated.

The WHO has estimated that one in eight of total deaths globally are the result of air pollution exposure, confirming air pollution as the world’s largest single environmental health risk. Air pollution is estimated to cause nearly half a million premature deaths each year in the European Union. In busy cities, where air quality is usually at its worst, the average life expectancy of people is reduced by over two years.

  • Outdoor air pollution has grown 8% globally in the past five years, with billions of people around the world now exposed to dangerous air,according to new data from more than 3,000 cities compiled by the World Health Organisation (WHO).
  • 80% of the people living in urban areas live with air pollution above WHO recommended levels
  • Health research from the past year has documented that air pollution at any level is not safe, like lead.
  • Carlos Dora, coordinator of the WHO’s Interventions for Healthy Environment program said: It is crucial for city and national governments to make urban air quality a health and development priority.  When air quality improves, health costs from air pollution related diseases shrink, worker productivity expands and life expectancy grows.
  • Director of Public Health for WHO said: “We have a public health emergency in many countries. Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health. It’s dramatic, one of the biggest problems we are facing globally, with terrible future costs to society,” Dr M. Neira, director of public health at the WHO in Geneva said: “The cost for countries is enormous. Air pollution affects economies and people’s quality of life. It leads to major chronic diseases and to people ultimately dying.”
  • Outdoor air pollution causesmore than 3m deaths a year – more than malaria and HIV/Aids – and is now the biggest single killer in the world.
  • The toll of deaths from air pollution is expected to double by 2050 and perhaps triple by 2060 as numbers of fossil-fuel dependent vehicles co is expected to double as urban populations increase and car numbers approach 2bn by 2050. 
  • “As urban air quality declines, the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma, increases for the people who live in them.  When dirty air blankets our cities the most vulnerable urban populations – the youngest, oldest and poorest – are the most impacted,” said Flavia Bustreo, WHO assistant director general, though air pollution impacts people of all ages. While all regions are affected, fast-growing cities in the Middle East, south-east Asia and the western Pacific are the most impacted with many showing pollution levels at five to 10 times above WHO recommended levels.

“Air pollution is the fourth highest risk factor for death globally and by far the leading environmental risk factor for disease,” said Michael Brauer, a professor at the University of British Columbia’s School of Population and Public Health in Vancouver, Canada. “Reducing air pollution is an incredibly efficient way to improve the health of a population” in the US and Canada as well as other places.  The deaths accounted in the 5.5 million annually worldwide are those from lung cancer, chronic obstructive pulmonary disease (COPD) and respiratory infections.

More than 5.5 million people die prematurely every year due to air pollution

New research, presented today at the 2016 annual meeting of the American Association for the Advancement of Science (AAAS), found that despite efforts to limit future emissions, the number of premature deaths linked to air pollution will climb over the next two decades unless more aggressive targets are set.  More than 5.5 million people die prematurely every year due to air pollution.  More than half of deaths occur in two of the world’s fastest growing economies, China and India. About 1.6 million people died of air pollution in China and 1.4 million died in India in 2013.

“Air pollution is the fourth highest risk factor for death globally and by far the leading environmental risk factor for disease,” said Michael Brauer, a professor at the University of British Columbia’s School of Population and Public Health in Vancouver, Canada. “Reducing air pollution is an incredibly efficient way to improve the health of a population.”

The research is an extension of the Global Burden of Disease study, an international collaboration led by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington that systematically measured health and its risk factors, including air pollution levels, for 188 countries between 1990 and 2013. The air pollution research is led by researchers at the University of British Columbia and the Health Effects Institute.

Additional facts about air pollution:

  • World Health Organization (WHO) air quality guidelines set daily particulate matter at 25 micrograms per cubic metre.  At this time of year, Beijing and New Delhi will see daily levels at or above 300 micrograms per cubic meter metre; 1,200 per cent higher than WHO guidelines.  While air pollution has decreased in most high-income countries in the past 20 years, global levels are up largely because of South Asia, Southeast Asia, and China.
  • More than 85 per cent of the world’s population now lives in areas where the World Health Organization Air Quality Guideline is exceeded.  Many recent studies document effects at levels lower than WHO’s and USEPA’s.
  • The researchers say that strict control of particulate matter is critical because of changing demographics. Researchers predict that if air pollution levels remain constant, the number of deaths will increase because the population is aging and older people are more susceptible to illnesses caused by poor air quality.  Young people and developing organs are also at risk; over half of the world’s population is 25 or younger.
  • According to the Global Burden of Disease study, air pollution causes more deaths than other risk factors like malnutrition, obesity, alcohol and drug abuse, and unsafe sex. It is the fourth greatest risk behind high blood pressure, dietary risks and smoking.
  • Cardiovascular disease accounts for the majority of deaths known to be from air pollution with additional impacts from lung cancer, chronic obstructive pulmonary disease (COPD) and respiratory infections.

University of British Columbia. “Poor air quality kills 5.5 million worldwide annually.” ScienceDaily. ScienceDaily, 12 February 2016. www.sciencedaily.com/releases/2016/02/160212140912.htm.

Tuberculosis, leading cause of infectious disease in world

Tuberculosis is the leading cause of death in the world from a single bacterial infection, and it kills 1.5 million people per year.  In the US, TB infects 4.6 per 100,000 people.

Tuberculosis is estimated to afflict approximately 8-10 million people and to cause 1.5 million deaths each year worldwide. The incidence of the disease is particularly high in low- and middle-income countries that are experiencing rapid industrial growth and increases in motor vehicle traffic in densely populated urban areas. By the year 2030, scientists estimate that 50 percent of the world’s population will live in urban environments.

Research published by Steyn in 2007 showed that combined production of CO, oxygen and nitric oxide should be used in future models of Mtb persistence.  Carbon monoxide plays a significant role in triggering tuberculosis infection.

Air pollution plays significant role in triggering tuberculosis infection:  study shows how carbon monoxide triggers Mycobacterium tuberculosis

A new study shows how carbon monoxide triggers Mycobacterium tuberculosis and a shift to a drug-resistant dormant state. TB latency is a global problem that results in tuberculosis escaping detection and treatment. In the study, the researchers worked with Mtb cells under biosafe laboratory conditions and found Mtb proteins ‘sense’ CO at the molecular level, much like the bacteria’s proteins sense other gases in the lungs. The CO interaction is what led to a series of biological steps that sent Mtb into latency. The finding holds political and social implications for speeding up clean-air measures as a way to improve public health, in addition to the environmental significance. The study holds promise for helping to discover new ways to fight extreme drug-resistant tuberculosis.

“We’re talking about huge socio-economic and public health implications,” said Steyn. One third of the world’s population is infected with undetectable forms of tuberculosis, which hinders screening and eradication efforts.  The finding adds to a growing understanding that exposure to high levels of CO through air pollution and cigarette smoke plays a role in tuberculosis infection rates.   Also, the study showed that low levels of CO present in the body are capable of triggering tuberculosis latency, Steyn said. Inflammation, infection and oxidative stress are among contributors to CO in the body.

University of Alabama at Birmingham. “Air Pollution, Smoking Affect Latent Tuberculosis.” ScienceDaily. ScienceDaily, 14 May 2008. www.sciencedaily.com/releases/2008/05/080513101721.htm

Exposure to diesel exhaust particles makes immune cells less responsive to infection, suppressing their function on a cellular level

Exposure to diesel exhaust is associated with changes in the function of important immune cells that protect against the bacteria that cause tuberculosis (Mycobacterium tuberculosis).  Exposure to diesel exhaust particles (DEP) suppresses the function of phagocytic immune cells (a type of white blood cells that ingest foreign particles, such as bacteria) on a cellular level, diminishing the ability of exposed individuals to fight off infection or suppress latent infection by these bacteria.

“In laboratory experiments using DEP generated from an automobile diesel engine as model air pollutant particles, and blood samples gathered from 20 healthy individuals, we demonstrated that exposure to DEP makes cells less responsive,” said Dr. Schwander, a co-author. “The cells, in effect, became desensitized to stimulation with the bacteria that cause TB,” he explained. “This effect was even greater in cells that had prior exposure to DEP than in those that had concurrent DEP and Mycobacterium tuberculosis exposure.  Because there is already epidemiological evidence that connects tuberculosis to cigarette smoking and some forms of indoor air pollution, it seemed logical to look at outdoor air pollution for a similar correlation,” Schwander added. “The models we used indicated that this may be the case. The next step is to see if these results can be confirmed by larger epidemiological studies.”

Sarkar, Y. Song, S. Sarkar, H. M. Kipen, R. J. Laumbach, J. Zhang, P. A. Ohman Strickland, C. R. Gardner, S. Schwander.Suppression of the NF- B Pathway by Diesel Exhaust Particles Impairs Human Antimycobacterial Immunity.The Journal of Immunology, 2012; 188 (6): 2778 DOI: 10.4049/jimmunol.1101380

University of British Columbia. “Poor air quality kills 5.5 million worldwide annually.” ScienceDaily. ScienceDaily, 12 February 2016. www.sciencedaily.com/releases/2016/02/160212140912.htm.)