Factories supplying material for garments sold by H&M, Asda, Next and Tesco are leaking toxic chemicals into rivers and the atmosphere, a new investigation has found.

Villagers in the area around a plant in India told investigators about cases of cancer, tuberculosis, reproductive problems, birth defects and stomach disorders, according to a report by campaign group, the Changing Markets Foundation.

Following one major pollution incident in October, two people died and 60 others were left seriously ill near a factory in Nagda, Madhya Pradesh, which supplies viscose (also known as rayon) to retailers. Locals told researchers that the deaths were a result of pollution at the site.

Investigators reported “visible and strong-smelling” pollution which had turned water dark red at multiple sites surrounding the plant in India which supplies viscose –a fibre increasingly favoured for making clothes.

Aditya Birla Group, the Indian conglomerate which ultimately owns the plant denies that the problems were linked to its operations. The Mumbai-based company is the world’s leading producer of viscose, providing about a fifth of the global market, meaning that many clothes purchased online and in the high street in the UK are made from its materials.

The report is the latest evidence of the environmental and human destruction wrought by cheap, mass-produced clothing and of the gulf between retailers’ pledges to clean up their supply chains and their actions.

A stream of water near Aditya Birla's viscose factory in Madhya Pradesh, India (Changing Markets)

An independent laboratory test of air samples taken outside the plant by the investigation team found that the level of carbon disulphide – a toxic chemical used in viscose production was 125 times the World Health Organisation limit.

Workers inside the factory may have been exposed to far higher levels of carbon disulphide because the chemical is highly volatile, meaning that it quickly breaks down when exposed to air, said Natasha Hurley, campaign manager at Changing Markets.

Women receiving medicine, reportedly following an increase in medical complaints near Aditya Birla's viscose factory in Madhya Pradesh, India (Changing Markets)

She stressed that, without more detailed data, it was not possible to categorically link the factory’s operations with the health problems that local people reported. However, the potential effects of carbon disulphide exposure have been known for more than a century.

Victorian physicians noted that it caused “insanity” in workers at British rubber factories in the 1870s. It is also known to disrupt hormones, cause the formation of plaques on the walls of arteries and cause symptoms similar to Parkinson’s.

A 2014 US study found workers at one US rubber factory who were exposed to the chemical were twice as likely to develop fatal heart disease as those who weren’t.

Steaming effluent near a discharge pipe from Aditya Birla's Indo Bharat Rayon plant in Indonesia (Changing Markets)

The new investigation found that another Aditya Birla viscose factory – in Indonesia – leaked discharge into a river in which children bathed, according to the report.

Water around the discharge pipe of the was found to be “extremely polluted” and not compliant with Indonesian water quality standards, which the report’s authors describe as “worst-in-class”.

The plant was temporarily closed down last month by local authorities after 11 villagers were rushed to hospital with suspected carbon monoxide poisoning because of the factory, local media reported.

The new findings about Aditya Birla’s operations come nine months after Changing Markets highlighted serious health and environmental concerns regarding a number of factories run by the company and other viscose manufacturers across China, India and Indonesia.

In that time, as conditions at the plant in Nagda, India, “markedly worsened”, the reaction from retailers and producers has been mixed.

One major viscose producer, Lenzing, has pledged to ensure what’s known as closed-loop production by 2022. This means that the harmful chemicals put into the process are captured and reused so they do not leak out into the environment. Changing Markets has called on other producers to do the same.

People queue up for clean water supplied by Aditya Birla's subidiary, Grasim Industries, reportedly after people fell ill in villages near its factory in October (Changing Markets)

In contrast, Aditya Birla’s response was to deny that there are any problems, Ms Hurley said.

“They have taken the approach of trying to disprove all of the evidence we have provided. Their mindset is not conducive to solving the problem.”

To support the company’s claim that it was appropriately treating run-off from the plant, the company supplied a photo of a plaque marking the opening in 1985 of an effluent treatment plant.

“That is not enough,” Ms Hurley said.

"They need to show that they are properly measuring these chemicals, as well as the results of that monitoring and how that information is being shared with the authorities.”

Changing Markets’ findings about the Nagda plant are supported by a local study by the Indian Institute of Soil Sciences which found that effluent from the industrial area may have contaminated the Chambal River and the groundwater in nearby villages.

Paul Roeland from the Clean Clothes Campaign demanded full transparency along the supply chain, coupled with proper inspections to begin to solve the problem.

“Due diligence on environmental and social protection is not an optional luxury but a fundamental duty of brands, suppliers, and investors, wherever production takes place,” he said.

The inauguration plaque of the effluent treatment plant which Aditya Birla says is evidence of its commitment to preventing pollution (Changing Markets)

Retailers respond

The conditions reported on the ground are in stark contrast with the ethical and sustainable image that many fashion retailers have increasingly tried to project.

In the five years since the Rana Plaza disaster which killed 1,138 low-paid garment workers after a factory collapsed in Bangladesh, the fashion industry has begun to implement efforts to increase transparency in its supply chains.

However, the production of fast fashion items is complex, often involving multiple countries, each with their own legal systems and languages, meaning that transparency has remained elusive.

To combat the problem, Changing Markets has produced a roadmap for the industry with series of steps to ensure that viscose production becomes more sustainable.

After the allegations in the report were put to retailers, several, including H&M, Asos, and Inditex, which owns Zara, pledged to meet the commitments contained in the roadmap which include mapping the full supply chain and ensuring regular, independent environmental checks.

A spokesperson for Asos, which also sources from Aditya Birla, said the company was “committed to addressing the issue with our sustainable sourcing and environmental policies and by engaging with our suppliers to transition to closed-loop production”.

A spokesperson for H&M said: “We fully agree with Changing Markets on what actions need to be taken within the viscose production process.”

The company said it had signed up to the roadmap produced by Changing Markets to lessen the environmental impact of the industry and is accelerating its use of sustainable viscose alternatives.

Next said: “The issues are both complex and very real – and therefore cannot be solved by any single party acting alone.

“Next is therefore seeking to join with others in the retail sector to work collaboratively on a long-term solution.”