Air Pollutant Benzo(a)Pyrene Linked to DNA Damage

An Eastern European study has discovered a link between a specific and potentially lethal type of high level air pollution exposure and a surge in DNA damage in those exposed to it.

According to the Czech Republic-based research team involved, one particular pollutant, benzo(a)pyrene, is responsible for an increase in so-called DNA-based biomarkers capable of making subjects more susceptible to cancer and other illnesses.

A biomarker, short for biological marker, is used as a standard medical and scientific reference point. As defined by the US National Institutes of Health, it represents a ‘characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.'

Benzo(a)pyrene is classified as a PAH (Polycyclic Aromatic Hydrocarbon) - one of a group of compounds that, when released as a result of industrial processes, pollutes the atmosphere. It's one of 16 such compounds identified by the US EPA as a priority pollutant and, as such, sits alongside the likes of pyrene, fluoranthene and anthracene.

Within the European Union, the benzo(a)pyrene air quality limit is a single nanogram for every metre cubed of air.

Air Pollution - DNA Damage

The Czech researchers' air pollution DNA damage study saw them explore the direct effect of benzo(a)pyrene on the body through looking at DNA samples supplied by 950 bus drivers and police officers, picked due to their deeply urban lifestyle, with outdoor working hours exceeding eight hours per day.

The 950 participants were involved in three earlier studies, carried out over a period of five years. All of them had attached monitoring devices measuring daily PAH exposure levels, while their DNA samples were examined through a technique dubbed FISH (Fluorescence In-Situ Hybridisation), which highlights chromosomal aberrations - where DNA stretches undergo structural changes.

The results obtained were groundbreaking: never before had a significant relationship been shown between PAH exposure, DNA adducts (DNA strands bonded to chemicals, like PAHs, responsible for the onset of cancer) and these chromosomal aberrations.

Benzo(a)pyrene Air Pollution

From their benzo(a)pyrene air pollution findings, the researchers especially noticed a seasonal fluctuation trend, with each participant exposed to 1.58 nanograms of benzo(a)pyrene per metre-cubed of air during January but 0.18 nanograms per metre-cubed of air in June. PAH exposure levels, as a whole, surged to 9.07 nanograms and 1.92 nanograms, respectively.

These exposure levels were correspondingly observed in the DNA samples, too.

The Czech study's results represent a potential concern, given that there's already a known link between cancer and benzo(a)pyrene air pollution exposure levels over and above the one nanogram per metre-cubed EU limit. One immediate outcome from this is new insight into the capability of the FISH technique, which might now go on to be used in future air pollution-based research.

See also:

Global City Air Pollution Report Lists PM10 Hotspots