The air we breathe in

A 65-year-old housewife in Bengaluru has been suffering from chronic obstructive pulmonary disease (COPD) for 10 years owing to chronic exposure to tobacco smoke—her husband is a smoker. Her symptoms include shortness of breath, tightness in the chest and mucus-producing cough.

COPD is a progressive disease, which causes permanent damage to the lungs and, over time, can affect basic activities like walking. Exposure to dust, infection and certain weather, such as humidity, accelerates it. COPD has no cure. The course of treatment she has to follow all her life includes using inhalers, protective vaccines against pneumonia, and exercise to maintain a basic level of activity.

In recent years, increasing outdoor air pollution in cities has been causing concern. But there is also growing evidence that the air within our homes and buildings can be as hazardous. According to a 2014 report by the World Health Organization (WHO), household air pollution led to 4.3 million deaths globally in 2012. It says South-East Asia had the highest number of such deaths, the primary reasons being COPD, ischaemic heart disease (characterized by reduced blood supply to the heart), stroke and acute lower respiratory disease. The report adds that although women experienced higher exposure levels, the burden of illness due to indoor pollution was almost the same for both women and men.

There are many factors that influence indoor air quality: dampsaness, microbial pollution, chemicals and particulate matter released while smoking and cooking, as well as local outdoor factors like re-infiltration of stove emissions (especially important for chimney stoves), and pollution from nearby traffic.

Priya Ramachandran, associate professor in the department of pulmonary medicine, St John’s National Academy of Health Sciences, Bengaluru, says: “Women are the most affected due to indoor air pollution. We see many women in their 50s and 60s affected by COPD. Many of them have husbands who smoke, but often do not bring this fact to light to the doctor. Hence, their condition is diagnosed late, resulting in respiratory failure.”

Ramachandran says that even if a person is not exposed directly to tobacco smoke, which contains cancer-causing chemicals, there are chances she/he will be affected by the residue on upholstery and curtains. “For many women diagnosed with lung, stomach and bladder cancers, the probable cause is exposure to chemicals from tobacco smoke at home. Children exposed to it at a young age have small lungs and are prone to asthma,” says Ramachandran.

According to WHO, dampness affects up to half of India’s indoor environments and is a strong indicator of risk for asthma and respiratory illnesses. Seepage, inadequate insulation and unplanned air pathways, or cool parts of air-conditioning units, can result in surface temperatures below the ambient temperature, leading to excess moisture and dampness. Excess moisture on indoor surfaces leads to growth of microbes, such as mould, fungi and bacteria, which emit spores, cells, fragments and volatile organic compounds. Microbial pollution is associated with respiratory symptoms, allergies, asthma and immunological reactions.

Ravindra Mehta, consultant, chest and intensive care unit physician, Apollo Hospitals, Bengaluru, says: “Increase in indoor humidity can be stifling and cause shortness of breath. Dampness causes mould or fungus to grow, which can cause lung disease.”

WHO lists certain chemicals like benzene, nitrogen dioxide and carbon monoxide as hazardous chemicals commonly present in indoor air.

Benzene is a genotoxic carcinogen. Its sources include smoke from burning coal and oil, cigarette smoke, wood-burning fireplaces, household products which contain petroleum-based chemicals, such as glues, paints and furniture wax. People who breathe in high levels of benzene may suffer from drowsiness, dizziness, rapid or irregular heartbeat, headaches and tremors.

Carbon monoxide is another indoor pollutant; the main sources are tobacco smoke and proximity to outdoor traffic. Clogged chimneys, wood-burning fireplaces, gas burners and other heaters, like portable space heaters, which are not properly maintained, could also vent carbon monoxide. Carbon monoxide binds to the haemoglobin in oxygen and reduces the body’s ability to carry oxygen to the organs. Inhaling even low levels can cause headache, nausea, dizziness and weakness.

Ramachandran adds: “Office spaces with poorly ventilated rooms can accumulate dust particles. Constant exposure to air conditioning dries the mucus membrane, causing sore throat and sneezing. Poorly maintained air conditioners harbour dampness and germs, making one more susceptible to colds and upper respiratory tract infections.”

Phthalates, a group of chemicals used in vinyl flooring, air fresheners and personal care products like soaps, shampoos and nail polish too have an effect. These chemicals can leach out and be ingested, inhaled or absorbed through the skin. Studies have shown that exposure to this chemical can cause asthma and disruptions in thyroid and testosterone hormone levels.

Dr Mehta says: “People living in old houses, containing lead paint or asbestos in the construction, can be susceptible to lead poisoning and lung diseases caused by asbestos dust. Lead poisoning can cause loss of appetite and weight, abdominal pain, vomiting, joint and muscle pain. Exposure to asbestos dust can cause lung inflammation, even cancer.”

PRECAUTIONS

Here’s what you can do to keep your office and home free of pollution

u Avoid smoking indoors

u To steer clear of microbial pollution due to dampness, temperature control and ventilation is important

u Use clean fuels such as LPG, biogas or solar energy; avoid wood, coal or kerosene

u Mosquito mats and liquids contain pyrethrin and allethrin, chemicals which can worsen an underlying condition such as asthma and allergy. Their long-term impact is not known

u Room fresheners can aggravate asthma. Long-term exposure to the chemicals in fresheners, however, has not been studied

u Poorly maintained air conditioners can cause upper respiratory tract infection. They should be cleaned and maintained on a regular basis.

—WHO guidelines and Priya Ramachandran, associate professor, pulmonary medicine department, St John’s National Academy of Health Sciences, Bengaluru