Nepal’s air quality is stubbornly the poorest in the world: Global Air report

Publish date : 4 April, 2019

State of Global Air Report 2019, pollution in Nepal

In 2017, air pollution was the fifth highest mortality risk factor globally and was associated with about 4.9 million deaths globally and 147 million years of healthy life lost. Ambient PM2.5 accounted for 2.9 million deaths, while household air pollution accounted for 1.6 million deaths. Ozone accounted for about 472,000 early deaths in 2017.

Nepal’s air quality is stubbornly the worst in the world, according to the State of Global Air Report 2019 prepared by Health Effects Institute and Institute for Health Metrics and Evaluation’s Global Burden of Disease Project.

The third annual State of Global Air report is prepared focusing on the two key indicators of air quality in particular: fine particle air pollution (particulate matter measuring less than 2.5 micrometers in aerodynamic diameter, or PM2.5) and ozone found near ground level (tropospheric ozone). The report also tracks the exposure to household air pollution from burning fuels such as coal, wood, or biomass for cooking.

WHO has established the air quality guideline for annual average PM2.5 concentration (which can enter the lungs and the bloodstream) is set at 10 µg/m3 based on evidence of the health effects of long-term exposure to PM2.5. For regions of the world where air pollution is highest, the WHO has suggested three interim air quality targets set at progressively lower concentrations: Interim Target 1 (IT-1, ≤35 µg/m3 ), Interim Target 2 (IT-2, ≤25 µg/m3 ), and Interim Target 3 (IT-3, ≤15 µg/m3 ).

The report reveals that, in 2017, the annual PM2.5 exposure was highest in South Asian countries with Nepal listed as the country with worst air quality increasing from 96 µg/m3 in 2015 to 100 µg/m3 in 2017. The exposure was 91 µg/m3 in India, Bangladesh (61 µg/m3), Pakistan (58 µg/m3), Bhutan (38 µg/m3). Maldives had the lowest PM2.5 concentration.

The region with the second-highest PM2.5 exposures was western sub-Saharan Africa, where Niger (94 µg/m3), Cameroon (73 µg/ m3), Nigeria (72 µg/m3), Chad (66 µg/m3), and Mauritania (47 µg/m3) had the highest exposures. Countries in North Africa and the Middle East experienced similarly high level exposures, where, Qatar (91 µg/m3), Saudi Arabia (88 µg/m3), Egypt (87 µg/m3), Bahrain (71 µg/m3), Iraq (62 µg/m3) and Kuwait (61 µg/m3).

In the region of East Asia, China had the highest PM2.5 exposures (53 µg/m3), while North Korea and Taiwan experienced concentrations of 32 and 23 µg/m3, respectively.

The 10 countries with the lowest national PM2.5 exposure levels were the Maldives, the United States, Norway, Estonia, Iceland, Canada, Sweden, New Zealand, Brunei, and Finland. Population-weighted PM2.5 concentrations averaged 8 µg/m3 or less in these countries.

The report analysis reveals that more than 90% of people worldwide live in areas exceeding the WHO Guideline for healthy air—a decrease slightly, from 96% in 1990 to 92% in 2017. Likewise, more than half live in areas that do not even meet the WHO’s least-stringent air quality target. Fifty-four percent of the population lived in areas exceeding IT-1, 67% lived in areas exceeding IT-2 and 82% lived in areas exceeding IT-3.

The sources responsible for PM2.5 pollution vary within and between countries and regions, the report reads. Dust from the Sahara Desert contributes to the high particulate matter concentrations in North Africa and the Middle East, as well as to the high concentrations in some countries in western sub-Saharan Africa.

In 2017, 3.6 billion people (47% of the global population) were exposed to household air pollution from the use of solid fuels for cooking. These exposures were most common in sub-Saharan Africa, South Asia, and East Asia.

An estimated 846 million people in India (60% of the population) and 452 million people in China (32% of the population) were exposed to household air pollution in 2017, the report reveals.

The major PM2.5 sources in India include household burning of solid fuels; dust from construction, roads, and other activities; industrial and power plant burning of coal; brick production; transportation; and diesel-powered equipment. The relative importance of various sources of PM2.5 in China was quite different, with a separate study identifying the major sources as industrial and power plant burning of coal and other fuels; transportation; household burning of biomass; open burning of agricultural fields; and household burning of coal for cooking and heating.

Globally, the proportion of households relying on solid fuels for cooking dropped from about 57% in 2005 to 47% in 2017, the report states.

In China, the proportion of households cooking with solid fuels fell from 61% in 2005 to 32% (452 million) in 2017, largely due to aggressive efforts to reduce household burning of coal for cooking and heating. Similarly, India reduced its proportion of households cooking with solid fuels from 76% in 2005 to 60% (846 million) in 2017 due in part to a major government program to shift households from solid fuels to liquefied petroleum gas.

However, the rates of solid fuel use remain high in places at the lowest level of sociodemographic development, particularly in eastern, central, and western sub-Saharan Africa. Among countries at this level of development, the proportion of households using solid cooking fuels in 2017 ranged from 22% (6.6 million) in Yemen to 65% (19 million) in Nepal to more than 99% (9.8 million) in South Sudan. Although rates are coming down in many countries of the world, the numbers of people potentially exposed may remain the same or even increase as populations continue to grow, the report further reads.

Air pollution consistently ranks among the top risk factors for death and disability worldwide. Breathing polluted air has long been recognized as increasing a person’s chances of developing heart disease, chronic respiratory diseases, lung infections, and cancer.

The 10 countries with the highest mortality burden attributable to air pollution in 2017 were China (1.2 million), India (1.2 million), Pakistan (128,000), Indonesia (124,000), Bangladesh (123,000), Nigeria (114,000), the United States (108,000), Russia (99,000), Brazil (66,000), and the Philippines (64,000).

According to the report, most of the disease burden attributable to air pollution (82%) stems from chronic non-communicable diseases. Air pollution accounts for 41% of global deaths from chronic obstructive pulmonary disease (COPD), 20% of deaths from type 2 diabetes, 19% of deaths from lung cancer, 16% of deaths from ischemic heart disease, and 11% of deaths from stroke. Air pollution also contributes to communicable diseases (e.g., 35% of deaths from lower-respiratory infection).

Air pollution collectively reduced life expectancy by 1 year and 8 months on average worldwide, a global impact rivaling that of smoking, according to the report. This means a child born today will die 20 months sooner, on average, than would be expected in the absence of air pollution.

In South Asia, for example, household air pollution contributes to an additional life expectancy loss of about 1 year and 3 months, bringing the total life expectancy loss from air pollution to 2 years and 6 months.

In sub-Saharan Africa, where more than 80% of people cook with solid fuels, household air pollution dominates the impact on life expectancy, accounting for 1 year and 4 months of the nearly 2 years in life expectancy loss from air pollution overall, the report states.