Among persistent organic pollutants (POPs), polycyclic aromatic hydrocarbons (PAHs) are a class of complex organic chemicals of increasing concern. They are commonly found in ambient air and some have been identified as suspected carcinogens. PAHs and their derivatives are produced by the incomplete combustion of organic material. In highly urbanised areas domestic heating and motor vehicles are the largest contributors of PAHs. As a consequence, populations living in these areas are exposed to pollutants that potentially have negative impact on their health (e.g. lung, skin, and bladder cancer, DNA damage and increased risk of cardiopulmonary mortality). The EU Directive 2004/107/EC sets annual average target values for particulate matter. Furthermore, this directive requires each Member State to monitor several relevant PAHs. Italy has placed PAHs on the 2009 national annual priority list, with the aim of developing a database able to support related policy actions. in addition to traffic and domestic heating, Rome, one of the most urbanised cities in the Mediterranean area, suffers air pollution from two large airports, a large landfill for municipal solid waste, two waste incinerators and an oil refinery located within the city suburbs. Particulate matter (PM10) levels in the city are above the legal limit, and the 2010 air quality limit values were unlikely to be met. Health problems related to increased air pollution in the city looked set to continue.
The EXPAH project aimed to address the environmental and health problems caused by the emission, dispersion and transformation of PAH compounds. Its overall goal was to identify and to quantify exposure among children and elderly people to PAH content in particulate matter in the city of Rome and to assess the impact on human health, in order to support environmental policy and regulation in this field. The project planned to adopt integrated approach, based on measurements and modelling techniques. Its target was to build a prototype assessment method to provide basic knowledge on concentrations of PAHs in the city and their health impact. Analyses will be carried out to evaluate the effectiveness of possible reduction measures. The work would contribute to the development, assessment, monitoring and evaluation of environmental policies at local and national levels. The obtained results would also provide a valuable support to EU legislation on PAHs.
The EXPAH project adopted an integrated approach, based on measurements and modelling techniques, to estimate the spatial distribution of the population’s exposure to PAHs and identify key determinants of high exposure levels – i.e. time, activity and location. The project also estimated the potential health effects on the target population. The modelling approach began with taking an emission inventory of the target area. The dispersion and transformation processes affecting these emissions were then simulated by a computer model to calculate the impact of PAHs on the air quality. PAHs exposure results were then used to assess the related health impacts. The potential effects on air quality of new EU and local policies were evaluated by modelling ‘what if’ scenarios. Based on the foreseen air quality impact, the corresponding effects on human health were then evaluated. This evaluation considered all involved processes, including indoor/outdoor infiltration factors, to estimate exposure in the visited living environments (taking into account the time spent in each of them).
The project targeted an important environmental problem, providing new data and tools to address it while taking into account existing EU policies. More specifically, it provided new evidence for the implementation of Directive 2004/107/EC which proposed a target value of 1 ng/m3 Benzo[a]pyrene (B[a]P) for the total content in the PM10 fraction averaged over a calendar year. This directive also suggests assessing the contribution of B[a]P in ambient air, and invites each Member State to monitor other relevant PAHs. However, PAHs are not continuously monitored as other regulated air pollutants, and therefore the time and spatial characteristics of the population exposure to PAHs are not well known. The project thus makes a significant contribution to EC legislation in this field, making suggestions for new mitigation actions.
Specific achievements included:
As a result of these activities, a series of detailed databases were set up and made available online in a GIS format:
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).