Are DIY Pollution Sensors Worth Using?

Over the last decade, public concern about air quality has increased as research has shown that pollution is responsible for many millions of premature deaths across the globe. One result of this growing awareness has been an increased demand for inexpensive, commercial air monitors that can be used in the home or workplace.

But while a public interest in the quality of the air we breathe can only be a good thing, the unreliability of these sensors could be cause for concern. With many of them not having faced rigorous regulation or testing to a high standard, they could be collecting false information and thus misleading the public about the quality of the air around us.

Filling a gap in the market

The most recent figures from the World Health Organisation (WHO) suggest that as many as 92% of the world’s population are exposed to unsafe levels of pollution, resulting in over seven million premature deaths per year.

Governments around the world are waking up to the reality of the situation and implementing rigorous air quality monitoring systems using the most sophisticated (and the most expensive) technology. However, concerned citizens who want to keep track of how much pollution they are exposed to have found themselves unable to afford such expensive equipment.

To cater for this demand, a new market in DIY pollution sensors has sprung up over recent years. Small, cheap and easily-assemblable monitors such as the WEPO watch and Speck have become more and more popular as people take a greater interest in the cleanliness of their immediate environment with regards to their long-term health.

Large margin for error

However, local air quality monitoring is not without its challenges. First of all, the pollutants which are primarily measured by such devices (including carbon monoxide (CO), ozone (O3) and nitrogen dioxide (NO2)) usually occur in concentrations too small to be picked up them.

This is especially true in wealthier countries where air pollution is not quite as serious a problem as other parts of the globe. Meanwhile, these contaminants are also blended with thousands of other compounds, making it difficult for the most advanced technology to pick them up – let alone a household sensor costing less than £50.

Finally, the sensors being used are often not suitable to the environments in which they are placed. For example, they are generally designed to work at a specific temperature, humidity or wind level. Fluctuations in any of these categories (as often can happen in homes and workplaces) could result in hugely distorted readings.

A time and a place

As a result, the efficacy of such systems in developed countries is still subject to debate. A recent paper published in the journal Nature called for greater regulation of these products before sending them out onto the market, where they could lead consumers to make misinformed decisions.

On the other hand, many nations around the globe cannot afford such luxuries. Moreover, these very same impoverished nations are likely to also suffer from elevated pollution levels and as such, DIY devices could serve a valuable function.

For example, places like India and China (where air quality monitoring has entered something of a new era) still suffer from incredibly high levels of pollution and heightened awareness of this problem, aided by a DIY pollution sensor, is certainly a step in the right direction. Having said that, it’s not prudent to place all of our faith in the accuracy of these devices until further trials have been conducted.