Mahdinia M, Adeli SH, Mohammadbeigi A, et al. - Researchers undertook this cohort study to determine respiratory disorders related to exposure to low levels of ammonia. Participants were 122 industrial workers. A significant rise in the prevalence rate of respiratory disorders was evident in the exposure group over 5 years. Significantly higher frequencies of these symptoms were noted in the exposure group vs non-exposure group. Respiratory functions reduced significantly in the exposure group and were identified to be lower in comparison with non-exposure group. Based on the findings, it was concluded that a risk for respiratory disorders can be conferred by exposure to ammonia lower than threshold limit value.