It is almost indisputable that smoking and drinking are harmful to our health. But there is a dangerous substance that we can't see or touch are harming us all the time, that is air pollution.
In 2015, about 9 million people died from diseases caused by air pollution, accounting for 16% of the total deaths, which is 3 times of the total deaths of AIDS, tuberculosis and malaria, and 15 times of the total deaths from war and other forms of violence.
In 2012, the International Agency for Research on Cancer of the World Health Organization (WHO-IARC) listed outdoor air pollution as a human carcinogen.
When we talk about the harm of air pollution to human health, women undoubtedly become the most direct victims.
Air Pollution May Lead to Stillbirth and Abortion
We should first understand a concept: pregnancy loss. Pregnancy loss includes stillbirth (fetal death during delivery at or above 28 weeks of gestation) and abortion.
According to a paper published on the Lancet, 7.1% of pregnancy loss in South Asia are caused by air pollution. It is estimated that 349,681 cases of pregnancy loss every year in India, Bangladesh and Pakistan are related to poor air quality.
South Asia has the largest population and the highest pregnancy rate in the world.
From 2010 to 2015, 178 million of the 698 million babies born worldwide were born in India, Pakistan and Bangladesh, but the death rate reached 35%.
Among them, Pakistan ranks fourth in the number of births, but its stillbirth rate is also the highest.
Coincidentally, the air quality in South Asia is not very good.
In 2002, a study by the American Cancer Society (ACS) showed that an average annual PM2.5 concentration of 10μm/m³ was considered below the average level most likely to have health effects.
That is to say, if the annual average concentration of PM2.5 in the air exceeds 10μm/m³, it will have adverse effects on the body.
According to the above paper on the Lancet, the average annual PM2.5 of Mumbai, Bangladesh and Pakistan exceeds 40μm/m³, which is 4 times higher than the safety value.
The paper also showed that if these countries meet India's air quality standards, they can prevent the pregnancy loss rate of 7% every year. Although this is a study in South Asia, it is of great significance to improve maternal and public health.
Air Pollution Has Been Hurting Women Since Pregnancy
In April 2018, a paper named Ambient Air Pollution the Risk of Stillbirth: A Prospective Birth Cohort Study in Wuhan, China published on the Int J Hyg Environ Health suggested that the probability of stillbirth increases with every 10μm/m³ increase in PM2.5.
Moreover, if women in the third trimester of pregnancy are exposed to carbon monoxide (CO), it will also increase the probability of stillbirth.
For women, in addition to the impact of air pollution on birth outcomes, more risks are also reflected during pregnancy and after birth.
Research on the impact of air pollution on female reproductive ability shows that endocrine disruptors (such as polychlorinated biphenyls) attached to particles may lose ovarian reserves, destroy oocyte fertilization, and damage embryo quality.
2. Pregnancy Complications
It refers to the abnormal glucose metabolism of pregnant women first found at 24 ~ 28 weeks of pregnancy, which is one of the most common complications during pregnancy.
A study in Taiwan, China and Denmark showed that air pollution (PM2.5 and SO2) during pregnancy will increase the risk of gestational diabetes.
Studies in the Netherlands and Japan showed that the occurrence of pregnancy hypertension is significantly associated with air pollution.
Meanwhile, the risk of pregnancy hypertension caused by different pollutants is also different. For example, PM2.5 and NO2 increase the risk of eclampsia.
3. Low Birth Weight
Low birth weight means that the weight of the newborn at birth is less than 2500g.
Low birth weight has a great impact on the late life quality of newborns, and is the main cause of death of children under 5 years old.
The More Housework, the Higher the Probability of Lung Disease
The average weekly working hours of housewives are about 77 to 105 hours, almost twice the modern standard working hours.
In the current division of labor between men and women, women still undertake most of the housework. This means that they have a greater probability of exposure to air pollution such as cooking, home heating and biomass combustion.
According to WHO, about 3 billion people around the world still use solid fuels (such as firewood, crop waste, charcoal, coal and animal dung) and kerosene for cooking in open fires and inefficient stoves. Every year, nearly 4 million people die due to indoor air pollution caused by cooking with solid fuels and kerosene.
Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by airflow restriction. "Emphysema" and "chronic bronchitis" refer to COPD.
WHO believes that burning solid fuels for cooking is the main factor that makes women suffer from COPD.
Among all the women who died of COPD, one third of them were caused by exposure to indoor smoke produced by cooking with open flames or inefficient stoves.
In January 2020, a paper named Cooking Fuels and Risk of All-cause and Cardiopulmonary Mortality in Urban China: A Prospective Cohort Study published on the Lancet, based on 170,000 research subjects and 9.8 years of prospective follow-up evaluation, found that compared with residents who have been cooking with clean fuels, residents who cook with solid fuels have an increased risk of death from respiratory diseases by 43%.
In addition, the incidence rate of lung cancer among women in the world has also gradually increased in recent years. The latest research of researchers from Canada, the United States and the American Cancer Society (ASC) shows that young women (between 30 and 49 years old) have a higher proportion of lung cancer than men.
Air pollution is one of the risk factors leading to lung diseases. The volatilization of indoor decoration materials and kitchen fumes will increase the probability of housewives suffering from lung cancer.
Especially for women exposed to kitchen fumes every day, a large amount of kitchen fumes released by frying and cooking will damage their lungs.
Although air pollution does harm to all of us, due to the special physiological structure and division of labor of women, air pollution does more direct harm to women.
Improving air quality is a long-term undertaking that requires the efforts of everyone. And we also hope that we can live in a better environment.
2. Tao Xue, Tianjia Guan, Guannan Geng, Qiang Zhang, Yong Zhao, Tong Zhu.Estimation of pregnancy losses attributable to exposure to ambient fine particles in south Asia: an epidemiological case-control study.Lancet Planet Health 2021; 5: e15–24
3. Kuai Yu*, Jun Lv*, Gaokun Qiu*, Canqing Yu, Yu Guo, Zheng Bian, Ling Yang, Yiping Chen, Chaolong Wang, An Pan, Liming Liang, Frank B Hu, Zhengming Chen†, Liming Li†, Tangchun Wu†.Cooking fuels and risk of all-cause and cardiopulmonary mortality in urban China: a prospective cohort study.Lancet Glob Health 2020; 8: e430–39
4. MeiLan King Han, MD, MSMark T Dransfield, MDFernando J Martinez, MD, MS.Chronic obstructive pulmonary disease: definition, clinical manifestations, diagnosis and staging.UTD. 2020-03-25
5. Scott T Weiss, MD, MS.Chronic obstructive pulmonary disease: Risk factors and risk reduction.UTD.Dec 17, 2019.
6. Yang S Tan Y Mei H et al.Ambient air pollution the risk of stillbirth: a prospective birth cohort study in Wuhan, China.Int J Hyg Environ Health. 2018; 221: 502-509
7. OSTRO B，SPADARO JV，GUMY S，et al. Assessing the recent estimates of the global burden of disease for ambient air pollution ：Methodological changes and implications for lowand middle-income countries [J]. Environ Res, 2018, 166: 713-725.
8. Ezziane Z. The impact of air pollution on low birth weight and infant mortality [J]. Rev Environ Health, 2013, 28 (2/3) :107-115.