As a long-term strategy to tackle pollution comprehensively and improve air quality in India, the Ministry of Environment, Forest and Climate Change launched its flagship initiative, the National Clean Air Programme (NCAP), in 2019. Among the core objectives of the Programme was to achieve reductions in particulate matter (PM) concentrations by over 20-30 percent by 2022-24 and by over 40 percent by 2025-26.

The programme envisioned achievement of National Ambient Air Quality Standards for Particulate Matter10 (PM10) concentrations in over 131 cities across the country with over 82 cities given targets of 3-15 percent annual reductions in PM10 levels in order to achieve the 40 percent target, and remaining 49 cities given a stringent 15 percent annual reductions target. The focus of the programme has been to improve air quality monitoring, raise awareness and build capacity through more monitoring stations, establish air information centres, and establish continuous ambient air quality monitoring stations (CAAQMS).

The NCAP brought Ambient Air Abetment into the public's glare, with the actions related to abetment coming under administrative review. Specifically, the NCAP targets reductions of up to 40% in 131 cities, including nonattainment cities and million-plus-population cities in 24 States. For five consecutive years, cities failing to meet National Ambient Air Quality Standards (NAAQS) were designated as nonattainment cities.

Methods like emission inventory, Source apportionment, and carrying capacity studies were undertaken for nonattainment cities to pinpoint the quantum of emission sources. These studies can give a general idea of the Indian subcontinent's air pollutants, precisely particle sources.

Considering that targeted cities are mainly impacted by dust as the primary particle source, abetment strategies are also primarily targeted at dust control. Consequently, NCAP has essentially become a particulate abatement programme as they are mostly the dominant pollutants in nonattainment cities.

Different source apportionment studies (sources of pollution) identify the following sources of particulate as having a significant impact:

• Road resuspension dust

• Construction dust

• Windblown dust 

• Long-range transport of dust

• Vehicular emission, particularly tailpipe emission

• Industrial emission 

Accordingly, almost all nonattainment cities are now focused on these areas in order to strengthen their abatement initiatives. The capital city of Delhi, for instance, tried and experimented with many abatement strategies but did not achieve the desired result. What could be the reason? Unfortunately, no convincing answers are readily available, and, hence, forces us to delve into the issues left out in the processes. 

When planning a pollution control strategy, the prime focus usually remains on combustion sources such as industrial, power plant, vehicular, and area-wide sources of emissions (brick kilns, hot mix plants, small-scale units, diesel generator sets, refuse burning, and so on). 

The strategy has been effective mainly for industries because the State Pollution Control Boards (SPCBs) primarily consider industrial pollution control – namely issuing consent to establish and operate, undertaking environmental impact assessments, etc. – as their main forte by working in designated industrial belts and monitoring channelized emissions from these industries.

However, a vital area of concern related to particulate matter is tackling coarser particles of the PM10 variety, which are generated from dust, mining, industrial fuel material handling, and so on. Besides their particulate imprint, they also provide a base for other toxins to settle, particularly in urban areas. As a result, a more effective way of controlling emissions must be to plan air quality management by focusing on a vital area – preventing fugitive emissions.

The menace of 'fugitive' emissions  

Fugitive emissions can be defined as unintended or overlooked emissions that are not emitted through conventional sources like chimneys or vents but, instead, come from leakages, processes, and storage and are generally uncontrolled. It may be in gaseous or fine particle form. Unlike the case of planned or designed emissions, no standards are formulated for fugitive or non-source emissions.

Industrial zones, in general, suffer from inadequate infrastructure characterized by poorly maintained roads prone to damage and potholes. This leads to frequent congestion as traffic management measures are often neglected. The absence of designated loading and unloading bays exacerbates emissions from raw materials, feedstock, and solid fuels. Better planning and improved infrastructure in these industrial zones are crucial to reducing emissions and improving air quality.

The Environment Protection Act mandates that raw materials should be transported in leakproof containers and that material handling should be dust-free through the effective use of water spraying with the transfer points being covered. Yet, these are often problematic enforcement areas because implementation eventually depends on better environmental practices followed by industry.

Regulators are, hence, required to conduct regular audits and inspections to monitor and implement rules and regulations. However, control measures and stipulations are largely prescribed as ‘guidelines’ instead of being implemented as definite norms for fugitive emissions.

Industries using fossil fuels and processing volatile chemicals can produce volatile organic compound emissions. Accordingly, sectors like cement, stone crushing, and power plants need stricter material handling and dust control measures. At all stages of industrial production, processes such as loading, unloading, crushing, conveying, grinding, packaging and handling post-combustion products, especially those like fly ash, have been a persistent concern that necessitates a comprehensive and monitorable framework.

Furthermore, the lack of proper planning for the disposal of industrial non-recyclable waste results in haphazard methods such as burning or open dumping and contributing to non-source emissions.

Counterintuitively, some specific sectors classified as non-polluting or green industries, or those with lower potential for emitting air pollutants, can contribute significantly to pollution due to their concentrated presence in a particular area. These include industries such as flour and rice mills, buffing units, engineering units, and even small roadside eateries that utilize coal or biomass as fuel sources, often operating with less efficient combustion methods.

Dry cleaning and laundry are other examples of domains that contribute to fugitive emissions and discharge significant levels of volatile organic compounds (VOCs) due to their extensive use of solvents. Fortunately, petrol pumps in India are now increasingly installing vapour recovery systems. Otherwise, they would considerably impact the well-being of personnel working on their premises, as a result of fumes escaping and polluting the environment, which can often be carcinogenic as well. 

Another factor that remains out of the purview of nodal authorities is the segment of industries that operate in non-industrial or non-conforming/designated unorganized areas that lack basic infrastructural facilities. These industries are not appropriately monitored because no department or organization owns specific jurisdiction over these unorganized industrial sectors.

As a result, these industries remained outside the monitoring net, and gross violations from fuel use and notable gaps in emission control can be observed. Inspection drives are often carried out to identify such units and come under the scrutiny of authorities, though only after people complain about their polluting processes and emissions, not as preemptive measures.

Need to revisit emission standards

These facts compel us to revisit the industrial emissions standards framework with more stress on fugitive processes and non-source and non-stack emissions from the industries and other sectors.

At the core of the problem is the need to develop and exact newer standards for each sector with proper weightage given to the size of the industry, namely the production system and its potential for emission. Instead of mere guidelines, more specific regulatory provisions should be framed so that industrial units can be held accountable, are monitorable and the nature of enforcement becomes more objective, scientific, data- and norms-driven.

Strict guidelines must be developed for developing industrial areas that handle non-source emissions. Manufacturing units functioning in non-industrial areas must be closely monitored through regular surveys and inventory. It must be accepted that industries that are operational in residential areas must either shift to industrial estates or be shut down.

If such measures are not readily enforceable, environmentally strong norms and practices should be enforced in non-industrial areas including the option of shifting out such production units from such identified localities.

Construction sources: Another source is the mismanagement of construction and demolition activities in our cities. As we know, construction never stops in our cities: the extension of houses and the demolition of older properties contribute to ambient dust. Major construction projects might follow some environmental laws; however, the quantum of small construction activities with higher numbers remains the biggest contributor, particularly in urban areas.

The lack of a system for proper disposal of construction waste or residual material after completion of the work is a key issue, even as steps required to control the emissions are seen to be half-hearted or not enforced effectively. Hence, the contribution of construction ‘dust’ to the pollution mix is quite significant. 

Construction material is sold everywhere in our cities: sand, bricks and other materials are available in all commercial areas but are not organized, stored or handled adequately. Windblown dust and vehicle-induced re-suspended dust are common nuisances in cities and rural areas.

At least in urban areas or areas with population concentrations, yards handling construction materials must be adequately planned and preferably covered to control the dust emission from these sites. Also, dust management practices across major and minor scales, utilization of reusable materials, and scientific dumping of construction and demolition waste must be thoroughly planned and executed.

The improper disposal of construction and demolition (C&D) wastes and municipal solid waste (MSW) has become a significant issue, leading to the blockage of water channels and stormwater systems. While a lack of coordination among agencies is frequently cited as a reason, urban local bodies such as the Public Works Department (PWD) and the National Highway Authority of India (NHAI), and so on, must ensure effective implementation of measures and enforce compliance with regulations in private construction.

Vehicular emissions: Discussions about vehicular emissions generally revolved around tailpipe emissions. Though tailpipe emissions are significant, other vital vehicular aspects like wear and tear in the brake shoe also contribute significantly to the emission process.

In the post-BS-VI fuel standards phase, the contribution from wear and tear of engine parts and brake shoes are among the essential factors determining the non-exhaust particulate matter sources of vehicular emissions. In contrast, tailpipe particulate matter is controlled by sophisticated exhaust systems that integrate after-treatment devices such as particulate traps.

Goods movement, loading, unloading, and distribution are other vital areas for focus. Dry ports and commercial or transport hubs are natural areas of concern and omnipresent across the country, particularly around major towns and cities. A vast number of vehicles transiting through such hubs cause substantial tailpipe emissions. Most of these nodal points are congested, and the resultant traffic bottlenecks make them a natural hot spot, mainly due to idling tailpipe emissions.

In addition to stricter laws for identifying polluting and unfit vehicles and facilitating cleaner vehicles to ensure lower vehicle tailpipe emissions, these areas must also have stricter monitoring. Accordingly, personnel of the enforcement agencies will also need to be effectively sensitized about all environmental laws and violations as they are often the first responders who can ensure timely action, as opposed to inspection teams in various departments who only act on complaints.

Be proactive, not reactive

In other words, proactive rather than reactive governance is key to dramatically transforming air quality governance.

A holistic pollution control measure must also involve multi-agency planning to facilitate smooth road traffic management, including eliminating bottlenecks and dynamically finding solutions to traffic congestion, a key catalyst for urban pollution.

Road sweeping through conventional means is often talked about because it coincides with when children go to school or just before peak traffic hours. Hence, manual and mechanical sweeping require attention to ensure their effectiveness. As we know, several cities have used it for almost a decade, though no effective standard operating procedures have been devised for the disposal of the collected waste.

The most commonly adopted method is to dispose of the collected material at landfill sites. On the other hand, exercise remains a pollution trigger. During manual sweeping, the practice of expansive water sprinkling to suppress the emitted dust is rarely seen to be followed. Similarly, manual sweeping is generally practised during the morning hours, coinciding with the school timings and resultant exposure of children to dust inhalation – a key reason why water sprinkling is essential for this exercise.

Another aspect of dust management is ensuring the design of street footpaths and medians according to norms, along with landscaping and greening measures to minimize regular dust intrusion.

Cities like Delhi have green areas, and most are parks with extreme climates; they develop bald patches in between, which may be a source of windblown dust. The hardy species of grass must cover these bald patches so windblown dust is limited, and the water sprinkling system may be used to control it while restoring greenery to bald patches. 

While crop residue burning remains a hot topic during winter, particularly in north India, frequent forest fires are also a major worrying thing, increasing, especially in the summer. Often, as it appears, the primary catalyst is the rampant transformation of forest areas for agricultural purposes. However, they become more devastating and widespread if fire mitigation practices are not followed. For example, the failure to develop fire ditches is the primary cause of fire, while extreme weather could be another trigger.

Another unique phenomenon is airborne toxic compounds formed in urban areas due to bird droppings, which threaten public health. Birds are fed near traffic intersections, and the area is not cleaned regularly, with the droppings drying and contributing to dust creation. Such allergens can be respiratory irritants and aggravate respiratory ailments. 

As we investigate, several more such ‘fugitive’ drivers and contributors can be identified. They are omnipresent, dispersed, difficult to control, measure, and monitor, and often neglected. Still, all such factors can collectively contribute to the air pollution and health impact crisis.

Pollution control is no longer a subject that deals with just apparent sources. Instead, the time has come to make concentrated efforts to control the emissions from all such sectors and sources. Most importantly, besides cleaning the air, better handling of raw materials, production processes, feedstocks, and fuels can improve efficiency and save resources and expenses incurred due to continuous losses. 

It is time for the stakeholders to pay considerable attention to fugitive emissions from industrial processes and other potent sources discussed above, and develop sustainable strategies to address them.