Air pollution as a determinant of food delivery and related plastic waste
April 22, 2021
On 22 April 2021, the world will commemorate Earth Day under the theme ‘Restore Our Earth’. Since the overwhelming majority of plastics are not recycled but end up in landfills, incinerated or as uncollected litter, consumers are encouraged to make their communities more sustainable by reducing their plastic waste. This includes joining the zero-waste movement and reducing single-use plastics from food deliveries.
While air pollution levels are relatively low in Singapore, the nation-state is not free of plastic pollution problems. The country uses about 1.76 billion plastic items each year, of which only a minuscule percentage can be recycled. Increased usage of plastic items means that precious land space on Pulau Semakau, an offshore island designated as a landfill, is being used up at an alarming rate. In addition, the ongoing COVID-19 pandemic has further escalated the use of plastic in the form of protective face shields, disposable masks, and takeaway food containers. The Singapore government has responded with its Zero Waste Masterplan to reduce plastic usage and protect the environment.
In China, 65 million food delivery containers were discarded each day in 2017. Ordering food to be delivered has become more and more popular in offices in Chinese cities and other locales in the developing world that are noticeably affected by air pollution, where workers seek to save time and minimise contact with visible haze or smog. The prevalence of pollution-induced deliveries creates a growing plastic pollution problem.
In ‘Air pollution as a determinant of food delivery and related plastic waste’ (Nature Human Behaviour, 2021), Associate Professors Junhong Chu (NUS Business School), Haoming Liu, and Alberto Salvo (NUS Economics) demonstrate how air pollution in cities in developing countries contributes to the popularization of food delivery services.
Their two linked studies examine how air pollution changed the consumption habits of office workers and the broader consumption pattern of food deliveries in Beijing, Shenyang, and Shijiazhuang, all big cities suffering from poor air quality.
In the first study, the researchers explore the relationship between office workers’ food delivery choices and changes in air pollution. A multi-wave panel survey of 251 office workers were asked to answer, each worker over 11 workdays, short questions on their work decision and lunch choice. Respondents submitted photos of their meals, whether they were eating a meal delivered to the office or had left the office to eat at a restaurant or a food stall. Over 3,000 photos revealed that the majority of delivered lunches were packed in single-use plastic with an average of 54 grams of plastic per delivered meal. This far exceeds the negligible amount of plastics used when eating a meal at a restaurant.
The researchers obtained 1-hour fine particulate matter (PM2.5) concentrations at the relevant Chinese Ministry of Environmental Protection (CMEP) air-monitoring sites and used the concentration of PM2.5 measured in micrograms per cubic meter of air (μg/m3) as a proxy for haze pollution levels. Using regression estimates, they found a strong causal link between consumption of food delivery and PM2.5 pollution. Deliveries increased by two-fifths and workers’ willingness to leave office buildings decreased by one third when PM2.5 rose from 10 μg/m3 to 110 μg/m3.
In the second study, the researchers analysed the order book of an online delivery platform to assess a broader customer base within the food delivery industry. Using 2016 records from orders in Beijing, the baseline probability that a user orders food delivery during a workday lunchtime is 8.7%. When PM2.5 increased by 100 μg/m3, the probability of food delivery increased to 9.3%, that is, by 7 percentage points.
The researchers note that the magnitude of the impact on delivery orders in the second study, while significant, is lower than that in the first study, because the order book reflects choices by both workers at the office and consumers who remained at home. A broad user base has more options than order deliveries on a hazy day, for example, consumers at home can access their home kitchen. Office workers’ lack of access to a kitchen, and often a food canteen, was one of the reasons for the higher rate of lunchtime deliveries. Notably, the impact of air pollution on food delivery is five times larger at lunchtime than at dinnertime.
Ultimately, disposable plastic material from food deliveries significantly contributes to the accumulation of plastic waste. Both studies demonstrated that haze markedly increased food delivery consumption. The researchers calculated that if all of China, with 350 million registered food delivery users, were exposed to a 100 μg/m3 increase in PM2.5 on a given day, , 2.6 million more meals would be delivered. This day’s pollution dose would generate an additional 2.6 million plastic bags and 2.6 million plastic containers, assuming one container plus one bag per meal.
These two connected studies of urban China provide insights into developing nations whose ambient air is routinely polluted. As online food delivery platforms increase in scope, the propensity for consumers to minimise the time they spend breathing polluted air is likely to drive up disposable plastic meal container use. Other consumption habits such as ordering grocery and food deliveries due to aversion to unpleasantly hot weather and minimizing human contact during the pandemic, could exacerbate plastic consumption. To counter these varied trends, the researchers recommend that local officials improve regulations and recycling efforts and incentivise alternative packaging to reduce plastic waste and environmental damage.
Read the article here.