Impact of construction dust and pollution on air quality

The presence of contaminants in household dust indicates indoor contamination and reflects human exposure within indoor environments. However, improper fact-checking near redevelopment and construction sites leads to dust dispersion, resulting in negative health effects on individuals.

With the urban population growing from 27.8 percent in 2001 to 34 percent in 2021, the demand for housing and infrastructure continues to rise, intensifying the issue of construction dust pollution. Over the past two decades, the surge in urbanisation and infrastructure development has been accompanied by an alarming increase in air pollution, with construction dust accounting for 59 percent of air pollution in India. Traditional construction methods, often characterised by on-site material breaking and crushing, have proven to be major sources of dust generation. Moreover, using outdated techniques and equipment in the construction industry further exacerbates the pollution problem.

Growing demand for dust control systems
Combatting air pollution is essential for protecting overall well-being and reducing the incidence of respiratory ailments like asthma. The accelerated industrialisation and heightened construction and mining operations in developing nations have substantially exacerbated air pollution. Additionally, indoor environments often contain elevated concentrations of trace metals like arsenic, chromium, copper, manganese, lead, and zinc compared to outdoor levels. Consequently, the need for effective dust control systems is expected to increase as a crucial solution to tackle air pollution.

Studies have indicated that house dust serves as a significant source of exposure to harmful substances, even including compounds that have been banned for a long time. Ingestion and inhalation of suspended or resuspended particles from house dust, particularly for infants and toddlers exposed to pesticides, are common routes of exposure. However, comprehensive guideline values for house dust currently need to be improved.

The adverse health impacts associated with dust exposure are well-documented. Particulate matter (PM), consisting of sulfates, nitrates, ammonia, sodium chloride, black carbon, mineral dust, and water, plays a significant role. Ground-level ozone, formed through reactions with gases in the presence of sunlight, is also a major component of photochemical smog. Effectively addressing air quality concerns, especially dust-related ones, requires implementing measures such as dust control systems. These systems are crucial in mitigating air pollution, safeguarding human health, and creating cleaner environments for everyone.

Dust control systems are vital in enhancing air quality by capturing and eliminating dust particles emitted during manufacturing. These systems utilise filters, blowers, and cleaning mechanisms to create a dust-free environment by capturing dust at its source through enclosures and hoods. According to a study by Grandview Research, the global market for dust control systems was valued at approximately USD 15.2 billion in 2018, and it is projected to grow at a compound annual growth rate (CAGR) of 4.2 percent until 2025. Increasing air pollution levels, growing health concerns, and stricter air quality regulations drive the market’s growth.

Construction dust vs air quality
The approval of over 2,500 real estate and infrastructure projects by the BMC (Brihanmumbai Municipal Corporation) has led to a significant increase in construction activities across Mumbai. Since 2018, ongoing infrastructure and building redevelopment projects have exposed residents to excessive dust pollution.

Data collected from the Central Pollution Control Board (CPCB) indicates that Andheri experienced the highest number of days with poor air quality between December 1 and March 2, coinciding with the demolition of a bridge. Several factors have contributed to the aggravated air pollution. These include the absence of green curtains around construction sites, inadequate sprinkling of water on debris during material loading and unloading, and the discontinuation of the BMC’s previous practice of sprinkling water on roads.

The prevalence of construction dust in any city highlights the urgent need for effective measures to mitigate its impact on air quality. Addressing these concerns requires a comprehensive approach that involves implementing dust control measures at construction sites, ensuring regular sprinkling of water to suppress dust emissions, and enforcing guidelines for green curtains and other preventive measures. By prioritising these actions, cities can improve their air quality and safeguard their residents’ health and well-being.

Magnitude of contribution
According to findings from the National Environmental Engineering Institute (NEERI), road dust accounts for a significant portion of the pollution load in cities. Unpaved roads, more prone to wind erosion, contribute approximately 45 percent of road dust. Paved surfaces contribute around 26 percent of the dust load. Construction activities contribute 8 percent of particulate matter emissions, and vehicles contribute 3 percent. Other sources include industries, the domestic sector, aircraft, marine vessels, open eateries, bakeries, and crematoria. In 2022, the System of Air Quality and Weather Forecasting And Research recorded high Air Quality Index (AQI) levels, indicating poor air quality. NEERI’s report to the state government highlighted that road dust accounted for 71 percent of all PM10 pollution in Mumbai, emphasising its significant impact on air pollution in the city.

Road dust is primarily generated while handling and processing road-building and construction materials, such as gravel and concrete. High levels of traffic activity and areas with increased road surface erosion and tire wear contribute to the re-suspension of fugitive particles. The turbulence generated by moving vehicles exacerbates the dispersion of these particles into the surrounding environment. Dust is generated during various construction processes, including excavation, demolition, and material transportation. Construction sites are significant sources of particulate matter pollution, adding to the overall pollution load in urban areas.

When dust and particulate matter particles become airborne and reach high densities, they can cause significant health issues. The smaller the particle size, the more susceptible we are to their harmful effects. In outdoor environments, factors such as sunlight, UV rays, rain, wind, and humidity interact in various ways, leading to diverse outcomes. On the other hand, Suhel Parker, Director, IAQA India Chapter explains if dust accumulates indoors and is not adequately controlled, combined with adequate moisture, it can promote the rapid growth of mould, which poses a severe health risk. Dust mites are a common allergen source in our homes. Therefore, it is crucial to regulate indoor dust levels. To achieve this, we can employ air purifiers and vacuum cleaners equipped with HEPA filtration, among other methods.

Challenges in air cleaner testing standards addressing IAQ
In response to evolving needs, standards have been developed to test the effectiveness of air cleaners. Initially, the focus was on protecting machinery and coils, and then reducing soiling. However, with growing concerns about indoor air quality, respirable particles, and the protection of products and HVAC equipment, a new test standard based on particle size has been developed.

“This standard, ANSI/ASHRAE 52.2P, utilises ASHRAE test dust #2 formulated according to ANSI/ASHRAE Standard 52.2P specifications. It is specifically designed for testing filters and components used in heating, refrigeration, and air conditioning systems. Additionally, this test dust has been employed in testing electronic equipment and various industrial and household components. WITH APPENDICES, the ANSI/ASHRAE Standard 52.2-2017 addresses two important performance characteristics of air cleaners: their ability to remove particles from the air and their resistance to airflow. Air cleaners are tested within specified airflow rates ranging from 0.22 m3 /s (472 cfm) to 1.4 m3 /s (3000 cfm). Coarse particles, such as those that accumulate on heat transfer surfaces, result in energy waste. On the other hand, fine particles cause soiling, discolouration of interior surfaces and furnishings, and may pose potential health risks when inhaled by occupants of the space.”

Certain air cleaners, specifically externally powered electrostatic precipitators or electronic air cleaners, may face compatibility issues with the dust used in this testing procedure. The dust employed in the test contains highly conductive carbon, which can lead to electrical short circuits. Consequently, this can diminish or completely undermine these devices’ effectiveness and negatively impact their Minimum Efficiency Reporting Value (MERV). Over time, the efficiency of these air cleaners may gradually decline in real-world applications, and their service life is influenced by factors such as conductivity and the quantity of dust accumulated.

Monitoring instruments for assessing air quality
Monitoring air quality is crucial for understanding and addressing particulate matter and other contaminants in the environment. In Mumbai, 21 AQI monitoring stations maintained by the Maharashtra Pollution Control Board and SAFAR are vital in assessing air quality levels. Monitoring instruments, such as those measuring PM concentration or particle size distribution, are essential for accurately assessing particulate matter levels. Amit G. Patil, Regional Manager at Mechmaark Filtech India Pvt. Ltd., emphasises the increasing demand for innovative monitoring instruments driven by concerns about indoor air quality and the urgent need to remove dust particles, especially those below PM 2.5 sizes.

Of particular concern are airborne dust contaminants originating from road construction industries. Examples include metalliferous dust, rock dust, finely powdered materials, coal dust, and crystalline silica dust. The accumulation of particles in the lungs is primarily influenced by PM10 and PM 2.5 sizes, with the latter causing irreversible damage and potential lung cancer.

Preliminary findings from NEERI’s study highlight the significant contribution of road construction and heavy traffic to PM10 pollution in Mumbai. Metalliferous dusts, rock dust, finely powdered materials, coal dust, and crystalline silica dust particles, particularly those in the PM10 and PM 2.5 range, can lead to pulmonary diseases and have severe health impacts.

Mitigating the impact of dust and indoor pollution on air quality
The future presents significant challenges in maintaining air quality, particularly with the expected rise in heat waves and increased use of air conditioning, contributing to greenhouse gas emissions. The sources of outdoor air pollution, including construction dust, are largely beyond the control of individuals, necessitating collective action by policymakers at local, national, and regional levels.

It is crucial to address the disproportionate burden of outdoor air pollution borne by low- and middle-income countries, where 89 percent of the problem persists. Regions such as WHO South-East Asia and Western Pacific face the greatest health burden, with air pollution playing a substantial role in cardiovascular illness and premature death. Access to clean household energy sources would also significantly reduce ambient air pollution in certain regions. Implementing measures such as barricading and enclosing construction sites, utilising green curtains, and employing sprinklers to control dust and air pollution can help mitigate their adverse effects.

The surge in urbanisation and construction activities has led to a significant increase in construction dust pollution, posing a threat to indoor and outdoor air quality. Construction dust, road dust, and other sources contribute to the overall pollution load in cities. The adverse health impacts associated with dust exposure are well-documented, emphasising the urgent need for effective measures to mitigate its impact. Dust control systems play a vital role in creating cleaner environments by capturing and eliminating dust particles at their source. Additionally, monitoring instruments for assessing air quality and innovative solutions for indoor air purification is crucial for addressing the issue. Collective action by policymakers and individual efforts is necessary to combat air pollution, protect human health, and create sustainable and healthier living environments for all.

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Amit G. Patil, Regional Manager, Mechmaark Filtech India Pvt. Ltd.
The demand for innovative monitoring instruments driven by concerns about indoor air quality and the urgent need to remove dust particles is increasing.

Suhel Parker, Director, IAQA India Chapter.
It is crucial to regulate indoor dust levels by employing air purifiers and vacuum cleaners equipped with HEPA filtration, among other methods.

Andrea Dalan, CAREL Sensors Platform Manager, Carel Industries.
Insulation can lead to decreased indoor air quality, necessitating a continuous air exchange. Therefore, combining insulation with an air-handling system is essential to ensure optimal indoor comfort.

Sourced references:
www.powdertechnologyinc.com
WWW.grandviewresearch.com
www.hindustantimes.com
www.who.int
www.theconversation.com
www.ashrae.com