Why construction dust is lethal for all and kids are the most vulnerable

Result: record levels of airborne particulate matter, PM2.5 (fine particles that are 2.5 microns or less in diameter) and PM10 (diameter of 10 microns or less) that together make up a lethal cocktail of pollutants which can be inhaled. The finer PM2.5 can travel to and embed in deeper parts of the lungs while PM10 usually deposits on the larger airways of the lung’s upper region.

Air Quality Index (AQI). (Credit: Amit Chakravarty)

Construction dust throws up particulate matter whose composition is a mixture of liquid and solid elements that include cement, sand, stone, wood, chemicals, and even metal.

Read Death By Breath Series – Mumbai holds its breath | Why construction dust is lethal | BMC’s rulebook gets a burial

Cement handling, common to all construction, generates PM2.5 and PM10 that can deeply penetrate the respiratory system. Inhaling these particles can cause lung irritation, inflammation, and worsen pre-existing conditions like asthma and chronic obstructive pulmonary disease (COPD), resulting in symptoms like continuous coughing and wheezing.

“Cement use releases chemical irritants like sulphur dioxide, nitrogen oxides (NOx), and volatile organic compounds (VOCs), which irritate the respiratory tract. Extended exposure can result in throat irritation, coughing, and breathlessness, potentially contributing to or worsening respiratory diseases,” says Samir Garde, Director of Dept of Pulmonology and Lung Transplant, Global Hospitals.

Studies have also shown that cement production may incorporate heavy metals like lead, cadmium and chromium, and their inhalation is also behind severe health problems, including neurological disorders, kidney damage, and cancer. Doctors emphasised that it is crucial for communities and policymakers to recognise the link between construction dust and air pollution.

Long-term (months to years) exposure to PM2.5 has been linked to premature death, particularly in people who have chronic heart or lung diseases, and reduced lung function growth in children. The effects of long-term exposure to PM10 are less clear, although several studies suggest a link between long-term PM10 exposure and respiratory diseases.

A landmark study by the California Air Resources Board showed how air pollution reduces children’s lung growth and function, impacts respiratory health in asthmatic children, and contributes to increased school absences.

Long-term (months to years) exposure to PM2.5 has been linked to premature death, particularly in people who have chronic heart or lung diseases, and reduced lung function growth in children. (Express photo by Amit Chakravarty)

Lung function growth rates

The 10-year study, conducted by researchers from the University of Southern California, tracked more than 5,500 children at 52 schools in 12 communities from elementary through high school, beginning 1992.

It found: significant lung function deficits most closely associated with exposure to nitrogen dioxide, atmospheric acidity, PM2.5 and PM10; decreased lung development may have permanent adverse effects in adulthood. And, significantly, children who move to cleaner communities with lower levels of PM have improvements in lung function growth rates.

Compared to adults, the impact of air pollution on children is more. Echoing the concern, Dr Bakul Parekh, secretary of South Asia Paediatric Association said that Infants, with a higher respiratory rate, typically breathe at approximately 30-60 breaths per minute. Toddlers, up to age five, tend to have a respiratory rate ranging from 20 to 30 breaths per minute. For children up to age 12, their respiratory rate may be up to 25 breaths per minute. “This increased respiration rate can lead to more significant inhalation of airborne pollutants, including fine particulate matter (PM2.5) and toxic gases. Also, due to their shorter heights, the intake of dust and micro particles at the lower stratosphere is more,” he said.

Children have developing immune systems, making them more susceptible to infections and allergens present in polluted air, said Dr Parekh. They have a limited ability to fight off respiratory infections, which can be exacerbated by air pollutants.

Dr Mukhesh Agrawal, head of paediatrics at Somaiya Hospital said, “The airways in children are still developing, and they have narrower air passages. This can make them more vulnerable to airway constriction and inflammation caused by pollutants, leading to symptoms like wheezing and shortness of breath.”

“Also, during Covid, they weren’t exposed to air pollution for two years. So now, when they encounter air toxins, common environmental elements, including allergens and pathogens, can lead to a compromised immune system. This reduced immunity makes children more vulnerable to respiratory illnesses, which can be exacerbated by air pollution,” said Dr Agarwal.

Studies have also shown that cement production may incorporate heavy metals like lead, cadmium and chromium, and their inhalation is also behind severe health problems. (Express photo by Amit Chakravarty)

Sanggita Checker, Consultant Chest Physician, Wockhardt Hospitals, underscores the direct impact of construction-related dust on the workforce. “Construction workers are particularly vulnerable to the adverse effects of airborne particles from construction activities. Prolonged exposure to construction dust can result in occupational diseases such as silicosis, a debilitating lung condition. Additionally, fine dust particles can enter the bloodstream, increasing the risk of heart and lung diseases in workers.”

Adequate workplace safety measures, including proper personal protective equipment and dust control, are essential to safeguard the health of those in the construction industry while mitigating the air pollution generated. As the impact of construction dust is quite significant on health, experts call for more awareness, being mindful while carrying out construction work, and being careful while handling debris.

Anumita Roychowdhury, Executive Director, Research and Advocacy, Centre for Science and Environment, said besides stringent implementation of guidelines, civic bodies must also take measures to recycle the waste material and debris from the construction sites as well as take measures to reuse the recycled debris again on construction sites. “Any type of active construction becomes a source of dust which can be harmful because of cement, minerals, grinding etc. The BMC needs to ensure that it develops a strong policy to control and mitigate dust. Furthermore, a lot of waste is generated during construction and demolition work, which must be disposed of carefully. A critical aspect is the segregation of this waste followed by transporting it to the recycling plants. This recycled waste can again be used for construction work.

On this front, there is a pointer from Delhi where it is mandatory that 10 per cent of the material used at the construction sites must be recycled. “The BMC too needs to create such a system and implement these measures,” she said.