Plastic pollution and flood risk: Estimating the number of people impacted globally

Objectives

Resource Futures was commissioned by Tearfund to research how plastic pollution contributes to flooding events, what the associated human health impacts are, and to what extent it is getting worse, by understanding trends in consumer plastic usage, population growth and climate change.

A key objective of this research was to estimate how many people are at risk of plastic-aggravated flooding, highlighting, in particular, the severe impacts being experienced by people living in low- to middle-income countries.

Approach

We started with a high-level literature review, to identify locations most at risk and to understand the connections between plastic pollution, flood risk and human health. A series of interviews were also conducted with experts, including people with in-country experience of plastic-aggravated flooding events.

Using findings from the literature review and interviews along with supplementary data, a methodology for a global statistic was developed to quantify the issue.

Outcomes

We estimate 218 million people are at risk of plastic-aggravated flooding worldwide. Approximately 41 million of these are infants, elderly people and people with disabilities and therefore at even greater risk of negative health-related impacts. Infants, for example, were found to be twice as likely to ingest polluted water than adults during a flooding event, severely increasing their risk of gastrointestinal diseases. It is likely that the figure of 218 million will increase in the future with a projected rise in mismanaged plastic waste, increasing periods of intense rainfall and higher populations living in slums. It was identified that regions in South and East Asia and the Pacific are experiencing the worst impacts, with 74% of our global figure residing in these areas.

Plastic-aggravated flooding is not a new phenomenon. There are reports of severe flood events being made worse by the presence of plastic bags in drainage systems as far back as the 1980s. However, some countries have only started to experience the effects of plastic-aggravated flooding over the last 10 years. The evidence gathered throughout the research demonstrated that plastic pollution in slums (densely populated urban areas with poor solid waste management and drainage infrastructure), is making flooding events more severe by blocking drainage systems. This is causing flood water to rise more quickly and stay around for longer, increasing the impacted communities’ exposure to polluted flood water. This is resulting in negative health outcomes including gastrointestinal diseases such as cholera and diarrhoeal disease.

“Tearfund works in more than 50 of the world’s poorest countries and our partners see firsthand the detrimental impact plastic pollution is having on communities globally. Around the world, from Brazil to the DRC, from Malawi to Bangladesh, we hear of plastic pollution making floods worse, so we commissioned this research to highlight the scale and severity of plastic-aggravated flooding.

“As the report demonstrates, the scale of this problem is significant and at present it is the poorest communities who are suffering most. This is an important message that those negotiating the UN Plastics Treaty need to hear and we were delighted to see the impact the report had on the ground and in the media at the negotiations in Paris. We hope that this will lead to further research in this important area and lend urgency to the development of a strong, legally-binding treaty which makes a real difference to people living in poverty.”

Impact

With UN member states negotiating a global treaty on plastic pollution, this research highlights and quantifies a key human health impact of mismanaged plastic waste, lending urgency to the talks. It demonstrates the socially and geographically unequal effects of plastic pollution, and illustrates the interconnected nature of the plastic pollution, climate and nature crises.