TEHRAN – With the onset of the coronavirus pandemic, air pollution has been marginalized despite being much deadlier, causing over 7 million deaths annually, while the virus has just taken less than 1.5 million lives worldwide so far.

Pollution (mainly air, water, occupational) contributed to 8.3 million annual deaths globally in 2019.

Air pollution is the fourth-highest cause of death surpassed only by high blood pressure, tobacco use, and hunger. It kills an estimated seven million people worldwide every year, while these days the pandemic is at the center of attention and air pollution is hiding behind the disease.

The pandemic compelled many countries to resort to a lockdown, and as a result, the daily average air quality index value drastically reduced to more than half in March-April 2020 in many countries, which had a positive impact on the environment, but sadly the effect was reversed as soon as they reopened.

Ambient air pollution

From smog hanging over cities to smoke inside the home, air pollution poses a major threat to health and climate.  Ambient air pollution accounts for an estimated 4.2 million deaths per year due to stroke, heart disease, lung cancer, as well as acute and chronic respiratory diseases.

Around 91% of the world’s population lives in places where air quality levels exceed WHO limits. While ambient air pollution affects developed and developing countries alike, low- and middle-income countries experience the highest-burden, with the greatest toll in the WHO Western Pacific and South-East Asia regions.

Sources of air pollution are multiple and context-specific. The major outdoor pollution sources include residential energy for cooking and heating, vehicles, power generation, agriculture/waste incineration, and industry. Policies and investments supporting integrated policies that support sustainable land use, cleaner household energy and transport, energy-efficient housing, power generation, industry, and better municipal waste management can effectively reduce key sources of ambient air pollution.

Air quality is closely linked to the earth’s climate and ecosystems globally. Many of the drivers of air pollution (i.e. combustion of fossil fuels) are also sources of greenhouse gas emissions. Policies to reduce air pollution, therefore, offer a “win-win” strategy for both climate and health, lowering the burden of disease attributable to air pollution, as well as contributing to the near- and long-term mitigation of climate change.

Household air pollution

Household air pollution is one of the leading causes of disease and premature death in the developing world.

Exposure to smoke from cooking fires causes 3.8 million premature deaths each year, mostly in low- and middle-income countries. Burning fuels such as dung, wood, and coal in inefficient stoves or open hearths produce a variety of health-damaging pollutants, including particulate matter (PM), methane, carbon monoxide, polyaromatic hydrocarbons (PAH), and volatile organic compounds (VOC). Burning kerosene in simple wick lamps also produces significant emissions of fine particles and other pollutants.

Particulate matter is a pollutant of special concern. Many studies have demonstrated a direct relationship between exposure to PM and negative health impacts. Smaller-diameter particles (PM2.5 or smaller) are generally more dangerous and ultrafine particles (one micron in diameter or less) can penetrate tissues and organs, posing an even greater risk of systemic health impacts.

Exposure to indoor air pollutants can lead to a wide range of adverse health outcomes in both children and adults, from respiratory illnesses to cancer to eye problems. Members of households that rely on polluting fuels and devices also suffer a higher risk of burns, poisonings, musculoskeletal injuries, and accidents.

Over 4,000 deaths in Tehran annually

Between 4,000 and 5,000 people residing in the capital city of Tehran lose their lives per year due to air pollution, according to statistics published by the ministry of health in 2019.

There are numerous vehicular trips per day in Tehran, which are the leading cause of air pollution in the capital so that the air in Tehran is amongst the most polluted in the world, Tehran City Council member, Arash Milani, said.

According to a report by World Bank published in April 2018, Tehran is ranked 12th among 26 megacities in terms of ambient PM10 levels. After Cairo, Tehran is the most polluted non-Asian megacity. In 2016, the annual ambient level of PM10 was estimated at 77 micrograms per cubic meter. This is almost four times the WHO’s recommended threshold of 20 micrograms per cubic meter.

The pandemic has indirectly produced both positive and negative effects on the environment, particularly in terms of air quality; in the city of Tehran, however, air reported even more polluted than it was before the outbreak.

Contrary to expectation, the average concentrations of both the PM2.5 and the PM10 were markedly higher.

Tehran more polluted

According to the statistics published by Air Quality Control Company, the Tehran air quality index (AQI) demonstrated 15 days of excellent air since the beginning of this [Iranian calendar] year (March 21), while during the same period last year, Tehraners breathed 25 days of clean air.

An AQI is used to communicate to the public how polluted the air currently is or how polluted it is forecast to become.

The index categorizes conditions according to a measure of polluting matters into excellent (0-50), acceptable (51-100), moderately polluted or unhealthy for sensitive groups (101-150), polluted (151-200), heavily polluted (201-300) and severely polluted (301-500).

This is while, last year over the same period 184 days of acceptable quality air reported in the city, while this year it was reported 181 days.

Since March 21, polluted air haunted the capital for 2 days which was almost dangerous for all the residents, which is the same as last year.

This is while, last year over the same period 45 days were unhealthy for sensitive groups, which

The leading cause of air pollution in the capital is PM 2.5, PM 10, and Nitrogen Dioxide (NO2).

How air pollution raises COVID-19 deaths?

Air pollution can cause health problems, like bronchial asthma, lung carcinoma, heart attacks, strokes, diabetes, high blood pressure, chronic lung/liver/kidney diseases, leukemia, skin diseases, eye diseases, and neonatal diseases. Many have been identified as pre-existing medical conditions that raise the chances of death from COVID-19 infection.

Emerging research has now suggested that breathing more polluted air over many years may itself worsen the effects of COVID-19 (8 percent increase in mortality from COVID-19 infection for every 1 microgram/cubic meter increase in air pollution), according to the Citizen.

The Doctors for Clean Air (DFCA) has warned that compromised lung function due to air pollution could lead to a serious complication in patients affected by the Covid-19.

Air pollution may also exacerbate symptoms of “long COVID”, which is a term used to describe symptoms of COVID-19 persisting weeks and months after recovery - with symptoms of cough, fatigue, diarrhea, joint pain, muscle aches, and lungs, heart, and kidney damage.

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