The Indian capital’s inherently dusty air is made worse by countless unregulated construction sites – and the production of bricks and concrete to feed them

Far out on Delhi’s southern and eastern fringes the rows of high-rises suddenly turn skeletal. The population of the Indian capital, already the second largest in the world, is forecast to grow by 9 million in the next 15 years; and despite a recent lull in new projects, areas such as Noida are a universe of worksites, cranes and workers.

The empty towers stretch as far as can be seen – which is only about 300 metres. Like much of Delhi on most winter mornings, Noida is blanketed in thick smog and a heavy dust that cakes windows and clogs throats.

A comprehensive 2016 study of what is to blame for Delhi’s poor air identified some obvious sources, such as car emissions, the city’s coal-fired power stations and rubbish fires both small and literally mountainous. But it also highlighted more unlikely culprits.

Dust kicked up by cars along Delhi’s vast and growing road network contributes between a third and 56% of the most harmful pollutants in the city’s atmosphere.

The city’s construction sites, and the production of the raw materials that feed them – such as bricks and concrete – are also an outsized contributor to the foul air that some lung specialists warn is making Delhi hazardous, particularly for children and the elderly.

In a country largely under construction – by some rough projections, around 70% of the buildings that will exist in India’s cities by 2030 are yet to be built – controlling the dust produced by roads and worksites is an important, but largely neglected, part of clearing Delhi’s air, according to environmental groups.

Landlocked by treeless plains and deserts, Delhi is inherently dusty. “It’s one of the reasons we can’t have air quality standards as strict or high as the US,” says Sarath Guttikunda, the founder of UrbanEmissions, an air pollution research group. “Our annual standard for PM2.5 pollutants is 40 units, but the World Health Organization’s guideline is 10.”

Facebook Twitter Pinterest Construction and demolition are the third-largest contributor of coarse pollutants. Photograph: Bloomberg/Getty Images

But poor building standards and antiquated practices, multiplied across thousands of worksites, make construction and demolition the third-largest contributor of coarse pollutants – strongly linked in a 2015 study to heart disease.

At one building site in Chittaranjan Park, an affluent south Delhi neighbourhood, half-covered piles of rubble spill out on to the pavement. No fences have been erected to keep the wind from whipping dust out into the street. Enormous mounds of dirt left in empty lots, or simply dumped at the roadside, are also a common sight.

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“The Indian construction contractor is trying to maximise his margins,” says Polash Mukherjee, a researcher with the Delhi-based Centre for Science and Environment. “If he’s constructing his house, he’s not required to go to a facility by law and dispose of the waste. Unless he’s forced by government to cover his trucks when he transport raw materials, he won’t do it.”

Builders aren’t just cutting corners: Delhi simply lacks the capacity to safely process the amount of construction waste it produces. A senior environmental engineer at the Delhi Pollution Control Committee told the Guardian current facilities allow for about 1,000 tonnes of waste to be processed per day, but the city produces an estimated 3,600 tonnes.

Run-of-the-mill construction activities take a hefty toll. The process of mixing concrete alone, for example, is estimated to contribute 10% of the coarse pollutants in Delhi’s air, according to an Indian Institute of Technology Kanpur study. Less polluting methods of producing concrete exist, but cost money. “Here it’s often mixed in a pit by manual labour,” says Mukherjee. “It’s cheaper that way, because there’s such a surplus of labour.”

A 2015 study of 19 large Delhi construction sites found the air quality around all of them exceeded safe limits by at least three times, with workers on these sites, mostly daily wage labourers, bearing the brunt. Almost none wear pollution masks, while a handful tie handkerchiefs across their faces to guard against the dust.

Facebook Twitter Pinterest Concrete is ‘often mixed in a pit by manual labour. It’s cheaper that way.’ Photograph: Bloomberg/Getty Images

Naresh Sharma, a cook on a site in Greater Noida, said workers were sometimes issued pieces of jaggery, a concoction of sugarcane and date palm believed to clear the throat and lungs. “It clears your throat from phlegm, but I don’t think it prevents damage,” says Sai Kiran Chaudhari, a leading pulmonologist at the Delhi Heart and Lung Hospital.

Two years ago, India’s environment court issued extensive regulations to clean up the city’s construction industry, mandating 50,000 rupee (£595) fines for builders who failed to cover their sites in tarpaulin, put up barriers, or sprinkle building materials with water before they were stored or transported. But Mukherjee says construction in Delhi is administered according to complex rules by numerous authorities, and in any case, “enforcement is very, very lax”.

Delhi itself has strong regulations, he adds, “but the biggest projects, the metros, hospitals or malls, are usually in suburbs outside the city, in Gurgaon or Noida, where those rules don’t apply”.

Even when clear orders are issued, they are routinely flouted. Brick production has been banned in Delhi for environmental reasons, but flourishes in nearby towns such as Dadri, in Uttar Pradesh state.

At RR Brickfields, one of the 18 kilns that dot the dry fields around the town, workers including children were collecting finished bricks from a furnace cut deep into the earth. Thick smoke billows from a chimney stack for almost the entire six months each year that the kiln operates. Studies have suggested India’s brick industry could contribute nearly 10% of India’s emissions of black carbon, a major contributor to climate change.

Facebook Twitter Pinterest Children working at a brick production site on the outskirts of Delhi. Photograph: Michael Safi

Since early 2016, brick kiln owners have been required to gain environmental clearance before firing their ovens. “But in some areas, people bribe officials. Sometimes they produce bricks secretly,” said the owner of the kiln.

He said he was still in the process of applying for a clearance and, despite the apparent signs of industry, insisted his kiln was not one of those operating.

Then there is the largest year-round contributor to the city’s air crisis: the dust thrown up by the more than 9 million cars that grind along Delhi’s poorly maintained, sometimes unpaved 33,000km road network. Dust has always been factor of Delhi life, but the particles released by traffic are particularly toxic, Mukherjee says.

“It mixes up with the vehicular emissions, the industrial pollution,” he says. Harmful pollutants bind to the dust and settle in the air, when they might otherwise be dispersed by winds.

Building more pavements would make “a big difference”, he says. So would planting vegetation along dividers and road shoulders. “Those bushes would get covered in dust, but it would prevent the dust from blowing further down the road,” Mukherjee adds.

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A significant proportion of Delhi’s pollution blows in from across the region, including from crop burning in Punjab and Haryana. There is growing awareness that Delhi’s air problem is really a regional one. Modelling produced for the Guardian by Greenpeace shows that air pollution increases the risk of heart disease for Delhi residents, and the risk of lung cancer by 62%. But the air in Amritsar, the Punjab capital, poses its residents a similar risk. The rates in Allahabad, in Uttar Pradesh, are even higher.

But lasting change will also involve tackling Delhi’s local pollution sources, Mukherjee says. “We know the solutions. We’ve known them for 30 years,” he says. “Implementation is the bane in India.”

Lung specialists such as Chaudhari are beginning to recommend to some older patients and those with chronic conditions to leave the city. “At one stage you have to think Delhi is not the place to live, you should look for a better option,” he says.

He says he aims to leave the city before the age of 50. “I’m serious,” he says. “Next time someone tries to trace me, I might be gone.”

Guardian Cities is dedicating a week to investigating one of the worst preventable causes of death around the world: air pollution. Explore our coverage at The Air We Breathe and follow Guardian Cities on Twitter and Facebook to join the discussion