Diesel Engine Exhaust Emissions And Petrol Engine Exhaust Emissions.
The TUC in the UK classify Diesel Engine Exhaust Emissions (DEEE) as one of the ‘biggest workplace killers’, and the HSE estimate that DEEE lead to 652 deaths per year from lung and bladder cancers (probably an underestimate). Long term exposure is also linked to respiratory disease, heart problems and other chronic and acute health effects. The British Safety Council (BSC) is also calling for Government action to ensure ambient air pollution is treated as an occupational health issue and adopt a Workplace Exposure Limit for DEEE. A recent report by the BSC linked air pollution with up to 36,000 early deaths a year in the UK.
Some of the largest occupational groups exposed to vehicle emissions are lorry drivers and heavy equipment operators, however a range of other occupations including car and truck mechanics (tyre and exhaust fitters) are also at risk from occupational cancers.
The International Agency for Research on Cancer (IARC) announced on 11th June 2012 that DEEE had been reclassified as a Group 1 carcinogen, associated with lung and bladder cancers.
The combustion of diesel fuel in engines produces a complex mixture of gases and particulates containing a range of known and suspected irritants and carcinogens including benzene, polycyclic aromatic hydrocarbons (PAHs), metals and particulate materials – particularly elemental carbon (soot). The composition of DEEE will depend on the type of engine, fuel and emission systems fitted. The speed and load of operation of engines is also important with increased DEEE associated with idling vehicles, and with cold and intermittently run engines.
Other harmful chemicals associated with DEEE include:
Acetaldehydes, acrolein, aniline, antimony compounds, arsenic, benzopyrene, beryllium compounds, biphenyl, bis(2-ethylhexyl) phthalate, 1,3-Butadiene, cadmium, carbon dioxide, carbon monoxide, chlorine, chlorobenzene, chromium compound, cobalt compounds, cresol, cyanide compounds, dibutyl phthalate, dioxins, dibenzofurans, 1,8-dinitropyrene, ethylbenzene; fluoranthene, formaldehyde, inorganic lead, manganese compounds, mercury compounds, methanol; methyl ethyl ketone, naphthalene, nickel, 3-nitrobenzanthrone, 4-nitrobiphenyl, nitrogen oxides, organic carbon, phenol, phosphorus, pyrene, propionaldehyde, selenium compounds, styrene, sulphur compounds, toluene and xylene.
Petrol engine exhaust emissions (PEEE) produce more carbon monoxide, but less oxides of nitrogen, sulphur oxides, aldehydes and particulate matter than DEEE. However, while exhaust emissions from diesel engines are usually more visible because they contain over ten times more particulates, some PEEE produce much higher levels of invisible, (inhalable) very small soot particles (10 – 20 nm in size) and more carcinogens!
Many airborne particulates (about 25%) originate from vehicle exhausts, especially from DEEE. High environmental increases in levels of particulate matter less than 10 μm diameter (PM10), in particular the sub 2.5 μm fraction (PM2.5), have been associated with increased cardiovascular or respiratory disease particularly among the elderly and susceptible individuals. The effects of exposure to these airborne particulates in the workplace have not been determined.
There are obvious workplace exposures airborne carcinogens contained in DEEE and PEEE in any garage, as well as possible exposure to welding fumes (also classified as possibly carcinogenic to humans – IARC classification group 1), rubber dust generated during tyre changes and brake dust.
The workforce (and customers) needs to be protected from such exposure by
1. reducing engine operation as much as possible,
2. restricting access to the workplace to essential staff only,
3. keeping the workplace well ventilated; at least 10 air changes per hour, and
4. installing tailpipe exhaust scavenger systems where practicable.
Air quality in the workplace, offices and waiting rooms can be further improved by using OrionAire units.
The ‘OrionAire’ range of units was developed for the removal of microbial cells, chemicals, odours and particulates from the air, utilizing Quantum technology. The units operate by generating a contained non-thermal plasma which destabilizes compounds and materials in the air using high-voltage, molecular disruptive forces and oxidative stress: organic compounds and inorganic molecules such as carbon monoxide (CO), ozone (O3) and nitrous oxides (NOx) are broken down into their component elements. Inert materials and particulates drawn through the plasma field are ‘supercharged’ and retained on the terminal electrostatic filter with efficiency greater than 0.1 microns.
Removal of chemicals.
Concerns about cabin and cockpit air quality from the Aviation sector prompted an extensive evaluation of this joint technology for removing Volatile Organic Compounds (VOCs) given off by heated engine oils and de-icing fluids. Extensive third-party testing demonstrated a consistent performance of 97% to 100% removal of a number of different VOCs after three passes using this technology:
Mean levels of atmospheric smoke residue with and without Orionaire technology.
Mountainheath Services Limited. Report number N1487 + Appendices: 17/08/2005.
Similarly, initial experiments on the removal of tobacco smoke from a Public House pool room demonstrated the effectiveness of the technology in removing 98.3 – 99.8% of tobacco smoke analytes, and 94.4% of carbon monoxide from the air during a 7 day trial period:
Mean level of tobacco smoke analytes in the atmosphere in a Public House pool room for a seven day period with and without the OrionAire technology in operation.
A Study into the Removal of Tobacco Smoke Analytes. (Microsearch Laboratories).
Removal of particulates.
Particulate removal by the terminal electrostatic filter.
The technology has been tested for compliance with the Airflow Quality Classes of ISO 14644-1. 1999. The main conclusions were:
- The unit passed validation testing in accordance with ISO 14644-1. Class 5, and
- The filter fitted, although not a registered industry HEPA type performs to a H10/ H11 HEPA filter manufactured to BS EN 1822.
Both the workforce and customers are exposed to unacceptably high levels of PEEE and DEEE in the garage environment. Short term exposure to engine exhaust can irritate the eyes, throat, and lungs, cause light-headedness and nausea, and exacerbate allergic reactions. Long-term exposure of the workforce can lead to occupational cancers.
The main control mechanisms in the garage environment to limit airborne exposures to exhaust fumes are ventilation and, where applicable (available?), exhaust scavenger units. Orion 4 Systems Limited has developed a new approach to limit exposure by removing PEEE and DEEE at source and in the working environment.
OrionAire units can be used as exhaust scavenger units when engines are idling or undergoing testing. Larger units can be used to recirculate/clean air in maintenance and office areas, reducing exposure to PEEE and DEEE. This is particularly important in the colder winter months when ‘natural’ ventilation may be restricted.
Dr. D.L. Webber. 24th May, 2019.