Every Breath You Take

Kate M. Serrano

Who would want to live in a polluted city? We all don’t because we know its health implications – runny nose, cough, sore throat, heart and lung problems to name a few. Poor air quality is caused by both natural and man-made pollutants. Apart from dust and sand particles, the more alarming causes would be traffic pollutants like carbon monoxide and nitrogen dioxide that when combined with ozone and sunlight cause air quality to drop.  Pollution is measured by the average number of particles in the air per cubic meter. This is referred to as the air quality index (AQI). As the AQI increases, health hazards brought about by air pollution also increases. The AQI also provides a scale of 1 to 10 to indicate health risks associated with air quality. For example, a number from 1 to 3 may mean air quality is ideal for outdoor activities while 7 to 10 means strenuous outdoor activities may cause throat irritation hence should be avoided. Late last year, a day after the World Health Organization published a report linking air pollution to lung cancer, Quartz came out with a list of the Top 10 most polluted cities in the world. These cities are not necessarily the biggest capitals but are the places where heavy industries take place. The city of Ahwaz, Iran which is a center for metal and petrochemical processing is on top of the list. Here is what the rest of the list has:

                        1. Ahwaz, Iran

2. Ulaanbaatar, Mongolia

3. Sanandaj, Iran

4. Ludhiana, India

5. Quetta, Pakistan

6. Kermanshah, Iran

7. Peshawar, Pakistan

8. Gaborone, Botswana

9. Yasouj, Iran

10. Kanpur, India

The World Health Organization regards air pollution as the world’s most serious environmental health risk. Did your city make the list? I hope not.

New Prospect for Clean Up of Contaminated Soil

By: Jessica Robertson

It is no secret that the high level of pollution of our planet, from sources like car engines or even cigarettes, is harmful. One particularly common contaminant, polycyclic aromatic hydrocarbons (PAHs), is a toxic tar substance that is believed to be a cause of cancer. These contaminants, and others, are often trapped in soil; PAHs, particularly, were thought to be mostly immobile in soil, binding to soil particles and being unable to dissolve in water. These qualities made clean up of contaminated soil quite a challenge.

A new study shows, however, a way to deal with these pesky contaminants. Some tiny microorganisms that do have the ability to move, like the unicellular slipper-shaped ciliate Tetrahymena pyriformis, have the surprising ability to take up the substance into the lipid layer of their cell membrane and act as a shuttle to the PAHs. This method means a much faster transport of the PAHs than the method of simple diffusion; furthermore, the ciliates are still able to transport the PAHs when there is no fluid flow, a situation where diffusion would be impossible.

Increasing the mobility of the PAHs by ciliate transport can increase the exposure of the PAHs to bacteria that can degrade them or to plant roots that can absorb them. These being the two main methods of biological treatment of PAH-contaminated soil, introducing such micro-organisms to contaminated soil can speed up what used to be a lengthy bioremediation process.