Background: Today, air pollution is one of the major problems in large cities including Isfahan. Methods: The objective of this study was to investigate the variations of ozone (O3), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen oxides (NOx), sulphur dioxide (SO2), and particulate matter (PM10) concentrations in different months at three stations and also to explore ...

Air quality assessment of the emission from power plant and traffic at Al-Taneem area located at the northern part of the Holy City of Makkah, Saudi Arabia, is investigated. Concentration levels of different pollutants including nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), carbon monoxide (CO), ozone (O(3)), methane (CH(4)) and total hydrocarbons (THC) as well as some meteorological parame...

Many governments subsidize regional rail service as an alternative to road traffic. This paper assesses whether increases in service frequency reduce road traffic externalities. We exploit differences in service frequency growth by procurement mode following a railway reform in Germany to address endogeneity of service growth. Increases in service frequency reduce the number of severe road traf...

asthma is one of the most common diseases in childhood, which has been increased during last decade because of epidemiological pattern changes with climate and industrialization of the communities. there are some controversies on the relationship between air pollution and asthma. tehran, as the capital of iran, is one of the densest populations and is one of the most polluted cities in the worl...

STUDY OBJECTIVE Assess associations between short-term exposure to gaseous pollutants and asthma hospitalisation among boys and girls 6 to12 years of age. DESIGN A bi-directional case-crossover analysis was used. Conditional logistic regression models were fitted to the data for boys and girls separately. Exposures averaged over periods ranging from one to seven days were used to assess the e...

The chemistry that occurs in the interstellar medium in response to cosmic ray ionization is summarized, and a review of the ionization rates that have been derived from measurements of molecular abundances is presented. The successful detection of large abundances of H(3)(+) in diffuse clouds and the recognition that dissociative recombination of H(3)(+) is fast has led to an upward revision o...