Comments on: 'Meteorological correlates and AirQ+ health risk assessment of ambient fine particulate matter in Tehran, Iran'

The recently published article (https://doi.org/10.1016/j.envres.2018.11.046), authored by Mohsen Ansari and Mohammad Hassan Ehrampoush (2019), was read with keen interest and in detail. The article aimed to investigate the correlation between ambient fine particulate matter (PM2.5, particulate matter with aerodynamic diameter 2.5 μm and smaller) and meteorological parameters, such as temperature, humidity, precipitation and wind speed. Additionally, the World Health Organization AirQ + software, updated in 2016 by WHO European Centre for Environment and Health, was applied to estimate all-cause and also five specific causes of death (namely, ischemic heart disease (IHD), cerebrovascular disease (stroke), lung cancer (LC), chronic obstructive pulmonary disease (COPD) and acute lower respiratory infection (ALRI)) due to long-term exposure to PM2.5 in Tehran from for the year spanning March 2017 to March 2018. It was reported that the authors obtained hourly concentrations of ambient PM2.5 from Air Quality Monitoring Stations (AQMSs) operated by the Tehran Air Quality Control Company (TAQCC). Other required data also were gathered from governmental organizations, including the Statistical Centre of Iran (SCI), the Civil Registration Office of Tehran, and the Ministry of Health and Medical Education. We believe there are a number of controversial issues that should be brought to the attention of readers, especially within the materials and methods sections, including “Description of Study Area”, “Air Pollution Data Monitoring and Exposure Assessment” and “AirQ+ Software”; and in subsequent sections, we also highlight some issues impacting the interpretability of the article.