As plastic production has skyrocketed over the past several decades, wealthy countries have benefited enormously — from increasingly lightweight, affordable products, for example. The full social and environmental costs of this plastic boom, however, have been disproportionately offloaded onto poorer people in the developing world.

According to an analysis published last week by the nonprofit World Wide Fund for Nature, or WWF, the costs of plastic across its life cycle — from production to disposal — are at least eight times higher for low- and middle-income countries than they are for high-income countries. In places like Brazil, Ethiopia, Fiji, and India, governments’ limited capacity to control or regulate plastic production has led to growing health risks from petrochemical plants’ toxic air emissions and chemical spills. Meanwhile, a pileup of discarded plastic threatens to overwhelm these countries’ waste management infrastructure, causing widespread land and water pollution.

“Our take, make, waste plastics system is designed in a way that unfairly impacts our planet’s most vulnerable and disadvantaged countries,” Alice Ruhweza, senior director of policy, influence, and engagement for WWF International, said in a statement.

As a third round of negotiations over a global plastics treaty begin this week in Nairobi, Kenya, WWF is hopeful that delegates will rally around policies to reduce plastic production and fund waste management in the developing world. “Business as usual could be a death sentence,” Ruhweza added.

Although environmental groups have long noted plastic’s outsize impact on developing countries, WWF’s report is one of the first to attempt to quantify that inequity. It takes into account the market price of virgin plastic, waste management costs paid directly by governments, and the costs created by the greenhouse gases emitted during the plastic production process — all of which are relatively easy to put a dollar value to.

Most of the cost disparity, however, comes from the end of the life cycle, when plastic is “mismanaged” — in other words, polluted into the environment. Mismanagement costs low- and middle-income countries at least $149 per kilogram of virgin plastic, compared to just $17 per kilogram for wealthier nations.

Read the full article about the cost of plastic by Joseph Winters at Grist.