Francisco Sánchez Soberón

ASSESSMENT OF THE HUMAN HEALTH RISKS AND TOXICITY ASSOCIATED TO PARTICLES (PM10, PM2.5 AND PM1), ORGANIC POLLUTANTS AND METALS AROUND CEMENT PLANTS

Particulate matter (PM) is the most dangerous air pollutant for human health. Particulate matter is composed of solid and liquid particles floating in the air and having different size and chemical composition. PMs are usually classified according to their size. Thus, those with a diameter smaller than 10 ?m are named PM10, those smaller than 2.5 ?m are known as PM2.5, and those smaller than 1 ?m are referred as PM1. Cement plants are one of the industries traditionally recognized as sources of PM. Although there are numerous studies dedicated to PM around cement factories, they tend to focus on PM10, ignoring the importance of smaller PM, which can reach deeper areas of the respiratory system. In the present thesis PM10, PM2.5 and PM1 were collected in an area influenced by a cement plant in different seasons. Subsequently, a physicochemical characterization of these particles was carried out to study their inhalation risks and the cement plant’s contribution to the total environmental PM. In addition, to evaluate their toxicity part of these particles was dedicated to performing in-vitro tests with respiratory cells. The highest PM levels were recorded in winter. In addition, it was found that more than 60% of the respirable particles are PM1. This last fraction contained the highest levels of some heavy metals and polycyclic hydrocarbons, presenting the greatest risks for the population. In-vitro tests revealed that the fine fraction (PM2.5) resulted in a higher overall toxicity than PM10. Finally, the contribution of the cement company to the total environmental PM was clear and dependent on the productive state of the plant. The results of this thesis highlight the importance of studying fine particles (PM2.5 and PM1) in environments influenced by cement factories.

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