Environment: Assessing the world-wide hazardous waste web

A world-wide ‘waste web’, which maps the movement of hazardous waste across the globe is reported in Nature Communications. The study helps identify the net exporters and importers of waste, and countries who are at the highest risk of waste congestion.

7–10 billion tonnes of waste are produced annually across the globe, including 300–500 million tonnes of hazardous waste, which includes waste that is toxic, flammable, explosive, corrosive or of biological risk. Countries trade waste and over the past 30 years the volume of hazardous waste traded has grown by 500%. There are economic incentives for waste trade, however, importer nations are often already contending with waste management and environmental health issues, and experiencing waste congestion (where the amount of waste outstrips processing capacity).

Ernesto Estrada and colleagues used data from 2001–2019 (except 2010) to track the trade of 108 categories of hazardous waste between countries and territories and developed a mathematical framework to model a world-wide ‘waste web’. The model identifies the time at which a given country reaches its carrying capacity and becomes saturated with a given type of waste. The authors identified 28 countries that are at a high risk from waste congestion, which could lead to improper handling of the material and potential pollution that affects the environment and human health. This included Mexico, India and Uzbekistan, who import large volumes of hazardous waste. The authors also suggest that countries including Germany, France, and the United States have evolved from more balanced waste flows to become predominantly net exporters, with China becoming the dominant net exporter of hazardous materials.

The authors suggest their findings will allow for the assessment of global scenarios of waste creation and policy changes, for example the COVID-19 pandemic and import bans, and the subsequent impacts they could have on waste congestion in individual countries.