Abstract
Background: Recurring annual asthma or asthma-like outbreak in Ahvaz City, Iran, has become a serious public health problem. A toxic gas, a chemical compound, or an allergen with unknown nature and mechanism leads to severe asthma outbreaks each year. Bronchospasm, cough, dyspnea, chest tightness, and wheezing are the main symptoms of these attacks. Oxygen and anti-asthma therapy are effective treatments in outbreak management. Based on our findings, it is hypothesized that vast amounts of ammonium nitrate used in agriculture underlay high concentrations of nitrate. This substance is transported by PM10 and is the main cause of the respiratory outbreak. Methods: The concentration of nitrate was determined by the ion chromatography method in dust samples during 2015-2016. Using spectroscopic methods, the effect of nitrate ions on hemoglobin oxidation and methemoglobin formation was studied. Results: Our results indicate that the concentration of ammonium nitrate in dust collected from indoor spaces is five times higher than the levels allowed amount in airborne pollutants. Our findings also indicate that this concentration of nitrate in the bloodstream can instantly increase methemoglobin percent to 18% with symptomatic consequences. Conclusion: The exact mechanism proposed by this study is that inhaled nitrate or nitric acid finally increases the nitrate in the circulation of affected individuals. Hemoglobin oxidation and methemoglobin formation are the subsequent events leading to methemoglobinemia with asthma-like reactions seen in Ahvaz respiratory syndrome. Restricting or even prohibiting ammonium nitrate application in agriculture seems to be an urgent measure to stop Ahvaz's recurring respiratory syndrome.
Highlights
I t is well known that respiratory outbreak associated with thunderstorms seen in the southwest of Iran, i.e. Ahvaz City, Iran, is mediated by dust particulate matters of PM10, PM2.5, and PM1 with 10, 2.5, and 1 mm diameters, respectively [1,2,3,4,5]
Based on the data obtained from Knoema in 2013, there is more than 917 percent increase in ammonium nitrate production compared to 2012 that correlates with more severe asthma of 2013 outbreak compared to 2012 [23]
Our ammonium nitrate determination indicates that the concentration of nitrate in dust collected from indoor spaces during this study was 268 ppm, which is five times higher than levels allowed as dissolved nitrate in the bloodstream (50 ppm) or as airborne pollutant [40]
Summary
I t is well known that respiratory outbreak associated with thunderstorms seen in the southwest of Iran, i.e. Ahvaz City, Iran, is mediated by dust particulate matters of PM10, PM2.5, and PM1 with 10, 2.5, and 1 mm diameters, respectively [1,2,3,4,5] These particulate matters carry large quantities of toxic chemicals, coal, oil, heavy metals, aromatic hydrocarbons, inorganic and immunogenic compounds [6,7,8,9]. Because of its proximity to major sources of dust in the Middle East countries, i.e. Iraq, Saudi Arabia, and Kuwait, this city is experiencing major dust events each year with thousands of milligrams per cubic meter of particulate matter [15,16,17] Considering their high capacity, PM particles carry large quantities of toxic pollutants on dusty days [18,19,20,21]. This substance is transported by PM10 and is the main cause of the respiratory outbreak
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Advances in Environmental Health Research
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
