The Effect of Air Pollution on Cancer in the Eastern Mediterranean Region: A Systematic Literature Review

Abstract

This study was conducted to assess the risk of cancer associated with air pollution in Eastern Mediterranean Region (EMR) by summarizing the existing knowledge from previous studies in the region and to identify knowledge and research gaps to support further research efforts. Combinations of search terms from three categories (“country” keywords AND ‘air pollution” keywords AND “cancer” keywords) were used to search for the relevant literature published between January 2000 and June 2016 using MEDLINE and other databases. Six case-control studies and three studies of other designs had assessed the association between air pollution and cancer in the EMR and met the inclusion criteria. These studies have assessed the effect of various indoor and outdoor air pollutants on the risk of different types of cancer. In this review, cancers were classified into: lung cancer; nasopharyngeal cancer; urinary bladder cancer; overall incidence of cancer in adults; and childhood cancer incidence. Limited epidemiological studies were found in the literature that properly address cancer incidence and air pollution in the EMR countries. Outdoor air pollution was not properly addressed in the included studies. Studies showed that using fuel for heating and living near an electricity generator and diesel exhaust exposure were significant contributors to lung cancer. NO2 has been shown to increase the risk of lung and breast cancer incidence. PAHs exposure did not increase the risk of cancer incidence. In conclusion, studies on the link between air pollution and cancer in EMR are limited to few studies in few countries. The reviewed studies have many limitations that make the evidence about the link between air pollution and cancer weak.