Safety devices for monitoring PAHs in workplace: a classification framework F. Facchini*, G. Mossa*, S. Digiesi* *Department of Mechanical and Management Engineering, Politecnico di Bari, Viale Japigia 182, Bari, Italy (f.facchini@poliba.it, g.mossa@poliba.it) Abstract: Polycyclic aromatic hydrocarbons (PAHs) are amongst the most harmful chemical compounds for human health. The carcinogenic effect of PAHs has been deeply investigated in the past and nowadays is well known. Due to the high concentration of PAHs in work environment, for some worker categories the cancer risk from exposure to PAHs is very high. Environmental monitoring of PAHs concentration in such workplaces could contribute in reducing the risk. Many quality air control systems are currently available on the market, are mostly based on chromatography and spectrograph techniques. Systems performances are dependent on the surrounding conditions of the environment in which they are adopted. In order to monitor air quality efficiently, a deep knowledge of the environment to be controlled is required. As a consequence, the choice of the right systems to be deployed is a very difficult task for stakeholders. The aim of this paper is to provide a state-of-the-art on the available commercial PAHs sampling and monitoring methods. A classification and a decision support tool in sensor selection is formulated, considering the jointly devices information about the work environment, the working conditions, and the technical and economical characteristics of the devices available on the market. The sensors can be classified by the operating criteria and dimensions. And, any comparative analysis can be done using: (a) technical features, such as the selectivity, the time resolution, the accuracy of the measurement, the response time and the reliability; (b) functional features, such as the portability, the modalities of employment, the process for determining the analyte concentration; (c) the aspects about the cost and the availability of the specific product. In this way, it will be possible to choose the detection methodologies and the most suitable typology of sensor for monitoring the air quality in the various working contests, thus to assure the safety and to preserve the health of specific categories of workers exposed to PAHs. Keywords: PAHs, Sensor, Environmental monitoring, Workplace safety, Classification methods 1. Introduction Polycyclic aromatic hydrocarbons (PAHs) are natural components of most fossil fuels. Although produced naturally by forest fires and volcanoes, most PAHs in ambient air are the result of man-made processes. Such processes include: • Burning fuels such as coal, wood, petroleum, petroleum products, or oil, • Burning refuse, used tires, polypropylene, or polystyrene, • Coke production, and motor vehicle exhaust There are approximately 100 different known PAHs in air, soil, foodstuffs and water. Once emitted to the atmosphere, the PAH weight influences the fate of the gaseous PAH mixtures. Heavier PAHs (more than four aromatic rings) tend to adsorb to particulate matter, while lighter PAHs (less than four rings) tend to remain gaseous until removed via precipitation. PAHs are absorbed through ingestion, inhalation, and dermal contact, the most significant endpoint of PAH toxicity is cancer (ATSDR, 2009). Not all PAHs are of the same toxicity because of differences in structure that affect metabolism; presently, the carcinogenicity of some PAHs, such as benz(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene, and indeno(1,2,3- c,d)pyrene has been well established in laboratory through tests on animals (ATSDR, 2011). Benzo(a)pyrene concentration in atmospheric air is considered as an “index” in the evaluation of carcinogenic risks for humans. In rural areas the average annual concentration of benzo(a)pirene is in the range of 0.5 – 6.0 µg/m³, while in metropolitan areas it is in the range of 5 – 30 µg/m³. In some specific workplaces the average annual concentration of benzo(a)pirene is up to 100 times higher than in metropolitan areas; as an example, in petrol stations the concentration of benzo(a)pirene is in the range of 25 – 563 µg/m³(Apostoli et. al, 2008). The Italian regulations with D.Lgs n.155 the 13th August 2010 (attachment XIII) defines a threshold levels for benzo(a)pyrene equal to 1 ng/m3, this value is calculated as emission average on one civil year. The U.S. government agencies have established standards that are relevant to PAHs exposures in the workplace and environment; these are summarized in table 1.