A photo of Indian cloth.

What colors India’s saris

UWM graduate student Subhomita Ghosh Roy studies the practice of dumping toxic dye water within India’s garment industry.

It takes a workforce of more than 6 million people to create India’s signature sari, a yards-long garment that has pleated, folded, draped and wrapped itself around Indian women for 5,000 years.

Among those 6 million are people running small family businesses that color sari fabric in a combination of chemical dyes and water. After shipping the fabric to factories, these businesses are left with gallons of dye water that’s contaminated with lead, copper, cadmium, iron, rubidium and other toxins, says Subhomita Ghosh Roy, a soil scientist and biological sciences doctoral candidate at UWM.  The water is dumped in backyards, which could be near animal habitats, lakes and even elementary schools.

UWM graduate student Ghosh Roy
Ghosh Roy plans to work as a soil scientist and professor in her native India after finishing her doctorate at UWM. (UWM Photo/Troye Fox)

The businesses are run by families trying to break into India’s middle class and stay there. Environmental protocol and procedures are expensive and loosely regulated.

Workers don’t take many safety precautions during the dying process, and often don’t wear gloves while repeatedly soaking their hands in chemical-laden water. “They told us: ‘We can’t keep up with the costs,’” says Ghosh Roy, who spent part of summer 2016 doing field research in the southern Indian state of Karnataka. “Something should be done about that.”

Then there are the environmental consequences of dumping the wastewater. To study that, Ghosh Roy collected and analyzed contaminated soil samples from two dyeing businesses with the help of Bangalore Institute of Technology researchers and Marissa Jablonski, her UWM instructor.

Ghosh Roy planted and tracked the growth of Lepidium, Sinapis and sorghum seeds. The three standard-indicator plants were grown in soil from a dye-waste site, as well as in uncontaminated control soil. After 72 hours, sophisticated imaging software revealed that plants in the uncontaminated soil grew much faster than their dye-contaminated peers.

Along with this growth-inhibiting effect, biomagnification is a main concern. Animals eat plants exposed to contaminated water and soil. Humans eat those animals and plants, and the human body excels at storing chemicals. The effects of heavy metals on human systems are not as widely studied in India as in the United States, where lead poisoning has had a devastating effect on urban families.

Ghosh Roy returned to Milwaukee after completing the field research, and her data analysis continues. Her dissertation research focuses on ecological contamination issues in Wisconsin. She plans on returning to India as a professor and soil scientist, and she hopes to improve workplace safety and environmental policy.