Does Air Pollution Affect Plastic Pollution Levels?

New research from the University of Singapore suggests that there is a direct link between poor air quality and plastic pollution. That’s because people in all sectors of society (but especially those working in an office job) are more inclined to order a takeaway lunch when smog levels are high. Since these meals arrive in single-use plastic containers, one type of pollution is directly affected by the other.

To arrive at their conclusions, the study authors concentrated on three of China’s most polluted cities: Beijing, Shenyang and Shijiazhuang. They gathered both qualitative and quantitative data and cross-referenced those numbers against air pollution records on 11 different days over a six-month period. The findings pointed unequivocally towards a connection between high levels of smog and increased plastic pollution.

Qualitative and quantitative

To gain a more comprehensive understanding of the topic, the researchers gathered data from two distinct sources. The first comprised of 251 office workers working in the three cities, who reported their lunch choices on the 11 days in question between January and June 2018. The second source was an online food delivery service, which services 350,000 people across the country. For context, that’s more than the entire US population.

They then mapped that data against air pollution records for the days in question. For the purposes of this research, the authors used particulate matter (PM) sensing to stand in as a proxy for air quality measurements and their results showed that for each 100μg/m3 rise in PM concentrations, the number of delivery orders from all segments of society rose 7.2%. Interestingly, the office workers were six times more likely to order a takeaway lunch on such days than other members of society.

A vicious cycle

So far, so straightforward. The researchers then had to determine how this increase in takeaway orders affected plastic pollution, so they asked the office workers to submit photographic evidence of their lunch. After poring over some 3,000 photos, the authors of the study estimated that each meal ordered from a restaurant used around 6.6g of plastic, while takeaway orders used a whopping 54g. Putting all of those statistics together, the report concluded that for every 100μg/m3 rise in air pollution, there was a corresponding 10g increase in plastic pollution.

That’s a concerning discovery, given that our seas and oceans are already being inundated with plastic waste. The vast majority of these kinds of takeaway containers and implements are single-use, meaning that once their purpose has been served, they are not recycled but instead end up in our waterways. Here, they can break down into even more dangerous microplastics, which can be mistaken as food by fish and marine mammals, interfering with their digestive systems and potentially killing them.

While that’s a distressing outcome, one positive interpretation of the study is that an improvement in air quality should be accompanied by a corresponding drop-off in plastic pollution, signalling that there is hope in the battle against all kinds of contamination.