How Can Social Media Be Used to Measure Pollution?

As most of us are well aware, social media is booming. There are a growing number of platforms with more and more users. Some of us spend a big chunk of our day checking the likes of Twitter, Facebook and Pinterest to keep in touch with our friends, our interests and the news. But now there might be another purpose for these sites. Researchers in the United States have found a way to use them to tackle pollution.

Tracking changes

Researchers at Rice University in Texas were testing whether social media can be used to track and measure air pollution. It was a collaboration between different departments, with both computer scientists and environmental engineers involved. The hypothesis? If people complain about pollution more on social media, then surely the pollution is worse. So how exactly did they do it?

The researchers needed a database. Luckily for them, the computer scientists had already collected a huge 112 million post sample for a previous study. These were posts from the Chinese microblogging site Weibo. They searched for key words in these posts like ‘haze’, ‘misty’, ‘dusty’ and ‘air pollution’, and created an Air Discussion Index (ADI) which uses these words as an indicator of how much pollution is being talked about online at any given time. By comparing them to their records of hourly pollution readings from the corresponding areas, they were able to calculate the accuracy of the posts.

Bigger sample, higher accuracy

While some are promising, their results are quite varied. Beijing was the most successful, with 88.2 percent accuracy for analysing pollution levels. The other areas had two potential reasons for their lower accuracy. There were less posts in the sample for these areas, but also the pollution isn’t as bad as in Beijing. They still demonstrated a promising level of accuracy though – Shanghai posts were 63% accurate, Guangzhou got 42% and lastly Chengdu with 36%.

Chinese air pollution

Beijing is one of the most polluted cities in the world. Their levels of particulate matter can be up to ten times worse than those in the US. It isn’t just particulate matter though. It’s estimated that Chinese power plants emit as much nitrogen oxide as all the cars in the world. The new data provided by this study shows that the problem isn’t something that can be avoided. It’s clearly affecting people and the day to day changes are even noticeable on the ground level.