Characteristics and applications of small, portable gaseous air pollution monitors

BackgroundTraditional approaches for measuring air quality based on fixed measurements are inadequate for personal exposure monitoring. To combat this issue, the use of small, portable gas-sensing air pollution monitoring technologies is increasing, with researchers and individuals employing portable and mobile methods to obtain more spatially and temporally representative air pollution data. However, many commercially available options are built for various applications and based on different technologies, assumptions, and limitations. A review of the monitor characteristics of small, gaseous monitors is missing from current scientific literature.PurposeA state-of-the-art review of small, portable monitors that measure ambient gaseous outdoor pollutants was developed to address broad trends during the last 5-10 years, and to help future experimenters interested in studying gaseous air pollutants choose monitors appropriate for their application and sampling needs.MethodsTrends in small, portable gaseous air pollution monitor uses and technologies were first identified and discussed in a review of literature. Next, searches of online databases were performed for articles containing specific information related to performance, characteristics, and use of such monitors that measure one or more of three criteria gaseous air pollutants: ozone, nitrogen dioxide, and carbon monoxide. All data were summarized into reference tables for comparison between applications, physical features, sensing capabilities, and costs of the devices.ResultsRecent portable monitoring trends are strongly related to associated applications and audiences. Fundamental research requires monitors with the best individual performance, and thus the highest cost technology. Monitor networking favors real-time capabilities and moderate cost for greater reproduction. Citizen science and crowdsourcing applications allow for lower-cost components; however important strengths and limitations for each application must be addressed or acknowledged for the given use

Measurements of ozone and its precursor nitrogen dioxide and crop yield losses due to cumulative ozone exposures over 40 ppb (AOT40) in rural coastal southern India

Measurements of ground level ozone (O3), nitrogen dioxide (NO2) and meteorological parameters (air temperature, relative humidity and wind speed and direction) has beenmade for 3 years from March 2007 to February 2010 at Nagercoil (8.2°N, 77.5°E, 23 m above sea level), an equatorial rural coastal site of southern India. The monthly average of daytime maximum of O3 concentrations ranged from 28 to 50 parts per billion (ppb) with an annual average of 19.8 ppb. Similarly, monthly average of NO 2 concentration ranged from 3.4 ppb to 7.7 ppb with an annual average of 5.3 ppb. The monthly variation ofmeteorological parameters shows the little changes being a coastal site. The estimated summer crops yield losses by 1.1- 15.6 from present O3 concentration level associated with AOT40 index 3.1-5 ppm h

Impact of the solar eclipse of 15 January 2010 on the surface ozone and nitrogen dioxide concentrations at Kanyakumari, India

359-363Solar radiation derives the chemistry of the atmosphere. Solar eclipse, being a rare event, provides unique opportunities for studying the changes in the atmosphere due to the sudden reduction in the incoming radiation. The effects of solar eclipse of 15 January 2010 on surface ozone (SOZ) and nitrogen dioxide (NO2) at  the coastal site, Kanyakumari (8o4’8’’N, 77o33’6’’E), Tamil Nadu, India, has been investigated in the present study. The behaviour of SOZ, NO2 and variation in meteorological parameters, like temperature, relative humidity (RH) were studied during this annular solar eclipse as well as one day before and after the eclipse. The experimental results showed that solar eclipse phenomenon affects the concentration of SOZ and NO2 as well as temperature and RH near the ground. Further, few minutes after the total eclipse, SOZ decreased to around 30 ppb, which is 25 ppb less than the normal and the level of nitrogen dioxide increased to 5 ppb. Also, it was noticed that during the course of the eclipse, the RH increased by 3% and temperature decreased by 4°C. The decrease in SOZ concentration was attributed to the reduction in the incoming solar radiation that affects the photochemical reaction. The observed increase in the NO2 concentration may primarily be due to the low photolysis rate of NO2

Surface ozone air pollution in Nagercoil, India

Abstract Ozone (O 3 ), one of the most powerful oxidants known, is a naturally occurring allotrope of oxygen. At high levels in the troposphere it is phytotoxic as well as cytotoxic. It is a secondary air pollutant formed by complex photochemical oxidation reactions. In this study, the measured surface ozone with one of its precursor nitrogen dioxide (NO 2 ) and important meteorological parameters at a semi-urban area during 2009-2010 has been analyzed. The maximum concentration of surface ozone was obtained during summer season (May 2009, 42.24 ppb) and the minimum was obtained during north east monsoon season (October 2009, 7.54 ppb). The results of this study show that the surface ozone concentration noticeably correlates with temperature (r=0.73) and NO 2 (r=0.93). It was found that not a single ozone exceedance day occurs during the period of study and the level of O 3 concentration is within the limit of WHO recommendation (50 ppb)