Formaldehyde

Formaldehyde was recently in the news … But more of this later. To start with, you may be asking, what is formaldehyde?

Formaldehyde is the non-UPAC name for methanal, CH₂O, the simplest of all aldehydes.

At room temperature, it is found as a gas (boiling point -19^oC). It does have a dipole moment but due to its low M_r (and hence weak London dispersion forces), it has a low boiling point.

It is found in the atmosphere and also in space. Due to its simple nature, it is found in comets and it is proposed that it is formed from the reaction of carbon monoxide with atomic hydrogen (a radical of hydrogen) to form HCO which then reacts with another hydrogen radical to form methanal:

CO + H → HCO

HCO + H → CH₂O

It is found in cells and is formed as an intermediate in chemical reactions. The amount of methanal formed in this manner will be tiny. Almost negligible. The reason why this is important is that if it makes its way into the body in larger amounts, it is a probable carcinogen.

So, if we are using methanal in the lab, as much as possible we need to minimize our exposure to it (face masks, fume cupboards, gloves are all needed).

And this is where our news article comes in.

The Sentinel-5P satellite, launched in October and tasked with tracking air quality world wide has indicated that there are very high concentrations of methanal above southern Asian and sub Saharan African countries.

SkywalkerPL (CC BY 3.0), via Wikimedia Commons

The reason for this is believed to be due to fire. Either coal fires or wild fires.

These reactions will produce carbon monoxide which, in the presence of UV light (and also at high temperatures), can react with hydrogen atoms (radicals) as outlined above.

More on the news article can be found here: https://www.bbc.co.uk/news/science-environment-44550091

The obvious problem with this data found by Sentinel is the worrying effect on the health of people living in these areas. Often, these are people living in impoverished conditions with poor access to health care anyway.

So, the big question is what is the solution? Should people be banned from burning wood and coal? Is it fair to pollute the air and also expose people to a carcinogen?

What are your thoughts on this important matter? I’d love to hear from you so please feel free to post your thoughts below.