Here are the 'oppressive' working conditions at the farms that supply Whole Foods, report shows

Whole Foods says its mission is to "nourish people and the planet," but workers at farms that supply the organic-grocery empire are often overworked and poorly treated, an investigation by Oxfam found.

Workers on sweet-potato farms in North Carolina that supply the Amazon.com Inc.-owned grocer reportedly put in 14-hour days in "oppressive heat with few rest breaks" and often with "very limited access to toilets," according to the report.

Though the farm workers are not Whole Foods Market employees, the allegations come just weeks after Amazon's chief executive, Jeff Bezos, came under fire for cutting medical benefits for almost 2,000 part-time workers at stores across America.

Whole Foods said it had initiated discussions with suppliers named in the report and have already begun work to schedule farm visits with third-party auditors. But the company takes issue with the findings, stating that Oxfam chose to "selectively publish the information we provided on our business practices" in response to its report, and that it chose not to initially share any level of detail on the allegations made against specific farms.

"Oxfam's latest report does not accurately reflect Whole Foods Market's long-standing efforts to address human rights and labor issues in our supply chain," the grocer said. "We have a proven track record of taking immediate action with suppliers when potential concerns surface and remain committed to supply-chain transparency and ethical sourcing, which are areas we continue to invest in."

Amazon bought Whole Foods in 2017 for $13.7 billion. It employs around 91,000 staff at 500 stores in the U.S., Canada and Britain.

Oxfam interviewed workers on farms and plantations in the United States, India and Brazil that are used by many of the big grocery chains. It said it found poverty-level pay, harsh working conditions and gender discrimination commonplace on the farms and plantations that supply tea, fruit and vegetables to the world's supermarkets.

Oxfam said: "In North East Brazil, researchers found evidence of poverty among harvest workers on grape, melon and mango farms. Farmhands also reported developing allergies and serious skin diseases as a result of working with pesticides and other chemicals without adequate protection. The farms supply Lidl, Sainsbury's, Tesco, and Whole Foods."

Not all supermarket chains cooperated with the study, Oxfam said. Walmart and Kroger , wouldn't decline or confirm to Oxfam whether the cited farms were in fact among their suppliers.

In a statement, Walmart said: "We appreciate the Oxfam research and report, which sheds light on important issues throughout the food retailing industry and the global supply chains that support it, highlighting areas for improvement as well as recognizing the good work we are doing." Kroger did not respond with a comment.

Oxfam interviewed workers on 50 tea estates in Assam, India, revealing that cholera and typhoid are common because workers lack access to toilets and safe drinking water. Half the workers questioned receive "Below Poverty Line" ration cards from the government because wages are so poor.

Referring to an earlier ranking of markets, a Tesco spokesperson said: "This is the second year in a row that Tesco has been assessed by Oxfam as doing most, of all major supermarkets globally, to ensure human rights are respected in food supply chains. We know there is always more to do and we are working ... to improve wages in the key produce, tea and clothing sectors and ensure working conditions are fair."

Fellow U.K.-based chain Sainsbury's and the German-based Lidl forwarded a comment from the British Retail Consortium industry body which said: "Our members are working hard to address existing injustices and continue to collaborate internationally with charities and business groups on this vital issue."