Gas monitoring station in hazardous environment with gases containing

Landfill sites collect tons of municipal solid waste (MSW) using an open dump mechanism, causing gases to emerge, which may cause disease and the greenhouse effect. Mainly, landfill environments are observed using a portable system that does not continuously monitor and measure emitted gas levels. It is also difficult to evaluate changes in landfill emissions over the long term unless they are monitored at regular intervals according to a detailed plan. This paper presents a new monitoring method to measure gas levels in landfill sites, which documents dynamic changes in gas composition concentrations over the long term. The system was placed in the middle area of the landfill and was charged using solar panels for convenience and greater efficiency during monitoring. While the instruments that are currently available are used for a specific parameter, this system can measure eight parameters, i.e., ambient concentration of methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), temperature, humidity, wind direction, wind speed, and voltage level. The system was evaluated regarding its ability to monitor gas parameters continuously.

Status of Air Pollution over the Last Three Decades in Thimphu City, Bhutan

With an increasing human population and vehicles, air pollution in Thimphu City is growing and causing a risk to human health, properties, and ecosystems. The population of Thimphu was 79,185 in 2005 but in 2017 it surged up to 114,551. An increase in the human population has also led to the rising demands for vehicles and thus increased the vehicular emissions in the area. Additionally, the use of traditional fuels, burning of waste and agriculture residues, forest fire, and transboundary pollutants are other sources resulting in poor air quality in Thimphu City. Air pollution data from journal articles, government documents, reports from national and international organizations, and books were reviewed. Concentrations of PM10, PM2.5, SO2, NO2 were increasing over the decades. The annual average PM10 recorded in Thimphu was 28 µg/m3 in 2005, 47 µg/m3 in 2010, 43 µg/m3 in 2014, and 42 µg/m3 in 2015. Winter months were found to have higher PM10 and PM2.5 concentrations. The 24-hourly average concentrations of SO2 ranged from 0.0 to 6.9 µg/m3 and NO2 8.2-26.6 µg/m3. There is a need for comprehensive studies to identify spatial and temporal variations in the ambient concentration of the pollutants in the area. Strict enforcement of the legal frameworks is essential for the mitigation of air pollution in Thimphu City.

Concentrations of Ground-Level Ozone on Petroleum Filling Stations in Urban West Region- Zanzibar

Ambient concentration of ground-level ozone was quantified from 14 petroleum filling stations in Urban and West districts allocated in urban west region Zanzibar between August and November 2019. In situ measurement was conducted for two separate sessions that involved before noon and afternoon in each day in the field using BH-4S Portable multi-gas detector. The analyzed data revealed both temporary and spatial variations of measured parameters. During phase1, the range of ozone was 4.8- 0.6 ppm. During phase2, the range of ozone was 14.2 - 4.5 ppm. The mean values recorded for ozone ranged from 0.6 ppm to 4.8 ppm for phase1, and from 4.5 ppm to 14.2 ppm for phase2. This study revealed that, ground-level ozone is at a point that calls attention tothe environment and health sectors.

Predicting the Number of Days With Visibility in a Specific Range in Warsaw (Poland) Based on Meteorological and Air Quality Data

Atmospheric visibility is an important parameter of the environment which is dependent on meteorological and air quality conditions. Forecasting of visibility is a complex task due to the multitude of parameters and nonlinear relations between these parameters. In this study, meteorological, air quality, and atmospheric visibility data were analyzed together to demonstrate the capabilities of the multidimensional logistic regression model for visibility prediction. This approach allowed determining independent variables and their significance to the value of the atmospheric visibility in four ranges (i.e., 0–10, 10–20, 20–30, and ≥ 30 km). We proved that the Iman–Conover (IC) method can be used to simulate a time series of meteorological and air quality parameters. The visibility in Warsaw (Poland) is dependent mainly on air temperature and humidity, precipitation, and ambient concentration of PM10. Three logistic models of visibility allowed us to determine precisely the number of days in a month with visibility in a specific range. The sensitivity of the models was between 75.53 and 90.21%, and the specificity 78.51 and 96.65%. The comparison of the theoretical (modeled) with empirical (measured) distribution with the Kolmogorov–Smirnov test yielded p-values always above 0.27 and, in half of the cases, above 0.52.

Assessment of Air Pollution status during COVID-19 Lockdown (Mar-May 2020) over Bangalore City in India

The Coronavirus disease 2019 (COVID-19), which became a global pandemic by March 2020 (WHO, 2020), forced almost all countries over the world to impose the lockdown as a measure of social distancing to control the spread of infection. India also strictly implemented a countrywide lockdown, starting from 24th March onwards. This measure resulted in the reduction of the sources of air pollution in general; industrial, commercial, and vehicular pollution in particular, with visible improvement in Ambient Air Quality. In this study, the impact of COVID-19 lockdown on the ambient concentration of air pollutants over the city of Bengaluru (India) is assessed using Continuous Ambient Air Quality Measurement (CAAQM) data from 10 monitoring stations spread across the city. The data was obtained from Central Pollution Control Board (CPCB) and Karnataka State Pollution Control Board (KSPCB). The analysis of the relative changes in the ambient concentration of six major air pollutants (NO, NO2, NOX, PM2.5, O3, and SO2) been carried out for two periods; March-May 2020 (COVID-19 lockdown) and the corresponding period of 2019 which was Non-COVID. The analysis revealed significant reduction in the concentration of ambient air pollutants at both daily and monthly intervals. This can be attributed to the reduction in sources of emission; vehicular traffic, industrial, and other activities. The average reduction in the concentration of NO, NO2, NOX, PM2.5, and O3 between 1st March to 12th May 2020 was found to be 63%, 48%, 48%, 18%, and 23% respectively when compared to the same period in 2019. Similarly, the comparative analysis of pollutant concentrations between pre-lockdown (March 01- March 23) and lockdown (Mar 24-May 12) period, shown a huge reduction in the ambient concentration of air pollutants; 47.3% (NO), 49% (NO2), 49% (NOX), 10% (SO2), 37.7% (PM2.5), and 15.6% (O3), resulting in improved air quality over Bangalore during the COVID-19 lockdown period. It is shown that the strict lockdown resulted in a significant reduction in the pollution levels. Such lockdowns may be useful as emergency intervention strategies to control air pollution in megacities when ambient air quality deteriorates dangerously.

Monitoring Chlorofluorocarbons in Potential Source Regions in Eastern China

Recent studies have indicated that Eastern China might be a potential source region of increased atmospheric chlorofluorocarbons (CFCs). To investigate this possibility, a field measurement was carried out from October to December 2017 for identifying the ambient concentration levels of representative trichlorofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trifluorotrichloroethane (CFC-113), and tetrafluorodichloroethane (CFC-114) at the residential and municipal solid waste (MSW) landfills and industrial sites in Eastern China. The ambient mixing ratios of CFCs at residential sites were almost within 20% enhancements of the global background sites. The highest levels of CFCs were observed at the MSW landfill sites. Moreover, CFC-11 and CFC-113 concentrations at MSW landfill, which was in service, were two times higher than that at completed MSW landfill. Mean concentrations of 322 pptv for CFC-11, 791 pptv for CFC-12, 91 pptv for CFC-113, and 16 pptv for CFC-114 at various industrial sites were higher than those at residential sites, but they were obviously lower than that at MSW landfill in use. A poor intercorrelation between the CFCs indicated that they did not come from the same source. Higher concentrations measured in this study compared with background sites indicates that MSW landfills could be an unintentional emission source and there are still substantial amounts of CFCs being stored in banks that may discharge CFCs into the atmosphere in Eastern China.

STUDY ON THE HEALTH IMPACT FROM USING BEEHIVE COAL STOVES IN HOUSEHOLDS IN HOAN KIEM, HANOI

The combustion of biomass and coal significantly contributes to the total health burden due to the emission of gaseous pollutants and particulate matter. To determine the personal exposure related to beehive coal stove cooking in Hanoi, an assessment study on 120 females in three wards (Tran Hung Dao, Phuc Tan and Chuong Duong) were conducted. Personal and ambient concentration of PM2.5 and CO (upwind, near source, far source) were simultaneously measured twice a day at each household by PATS++ equipment developed by Berkeley Air Monitoring group. The concentrations of PM2.5 in three wards were in range of 10-186, 12-441, 9-59, 3-271, and 9-260 µg/m3 while those of CO varied from 100-3000, 300-260000, 200-29000, 300-255000, and 2000-36000 µg/m3, for upwind, near source, far source, indirect exposure and direct exposure samples, respectively. The estimated COHb% for direct exposed group was higher than indirect exposed group in the three wards. Consequently, directly exposed group was suffering a higher risk. All directly exposed respondents and 75% of indirectly ones were experienced COHb% calculated in blood exceeding safe threshold for health of WHO guidelines. There has been increased risk for both exposed group if the coal beehive stove placed indoor. The calculated levels of incremental life cancer risk (ILCR) posed by PM2.5 in the three wards ranged from 1.6E-06 to 3.8E-06 daily, indicating moderate cancer risk to community that should be study further to protect public health.

Comparative Study of Various Methods for Trace SF6 Measurement Using GC-µECD: Demonstration of Lab-Pressure-Based Drift Correction by Preconcentrator

This study presents a high-precision method, using a preconcentrator–gas chromatograph with microelectron capture detector (GC-μECD), to measure SF6 at ambient levels. Carboxen 1000 was used as an adsorbent for the preconcentrator and exhibited a high adsorption efficiency for N2O and SF6 and low adsorption efficiency for O2. This enabled the selective removal of atmospheric O2 from analytes and improved repeatability of the SF6 peak that followed the O2 peak, in a separation column of activated alumina F1. In addition, the increased sensitivity resulting from preconcentrated SF6 improved the signal-to-noise ratio. This led to better analytical precision in comparison with other measurement methods including the conventional and forecut–backflush (FCBF) methods. The precision-to-drift ratios of the conventional, FCBF, and preconcentration methods were 0.11, 0.10, and 0.03, respectively. Analytical precision of the preconcentration method was 0.08% for 10 consecutive injections; this was the best among the three methods. The long-term drift of the SF6 response was inversely proportional to the laboratory pressure. Based on this finding, room pressure can be used to correct for ECD signal drift, with an uncertainty of 0.14% over a 48-h period, using the preconcentration method. Another advantage of the preconcentration method was the excellent linearity of the SF6 response to a wide range of concentrations, including its ambient concentration.