The environmental health catastrophe in Urmia Lake and asthma disease: a cohort study

Background: Urmia Lake of Iran used to be the largest saltwater lake in the world. It has now disastrously shrunk to 10 percent of its previous size. This study aims to investigate the impact of this environmental catastrophe on the occurrence of asthma. Methods: The whole population of ten districts in the area were investigated in this retrospective cohort study: "Exposed group" in the neighbouring areas of the lake, "Not exposed group 1" with medium distance (65 km) from the lake, and "Not exposed group 2" with more than 160 km from the lake. Clinical diagnosis of asthma was performed by the family physicians in the whole population. Results: The occurrence risk of asthma in "Exposed group" was 1.85 times higher (CI95%: 1.1- 3.0) than of "Not exposed group 1". The risk of disease, similarly, in "Exposed group" was 1.44 times more (CI95%: 0.9-2.3) when compared to "Not exposed group 2". Conclusion: The country and provincial authorities should consider this hazardous climate change in the region seriously before it becomes a harmful event for millions of people living in the area.