Mean Carbon Monoxide Concentrations Research Articles

QUANTIFYING THE IMPACT OF TRAFFIC-RELATED EMISSIONS ON AIR QUALITY IN KANO CITY, NIGERIA

The aim of this study is to assess the concentration of traffic related air pollutants at some major traffic junctions in Kano metropolis, it comprised of carrying traffic count in the vicinities so as ascertain the sources of the pollution and identify the level of carbon monoxide (CO), nitrogen dioxide (NO 2), Sulphur dioxide (SO 2) for a period of six weeks. Traffic density was estimated via manual counting using tally sheet system. Crowcon gasman to air samplers ware used to measure the concentrations of gases emitted into the atmosphere at the selected locations. A total of 126 samples of air quality measurements were taken out for three hours, with each hour devoted to morning, afternoon and evening peak periods. Results obtained were compared with National Environmental Standard and Regulatory Enforcement Agency (NESREA) guideline limits. Data were analysed using statistical package IBM SPSS version 16.0 to compute descriptive statistics, Pearson correlation, regression analysis and one sample t-test. There was a correlation between CO, NO 2, SO 2 and traffic volume in the entire junctions, and most of the correlation obtained may be attributed to the high vehicular volume in the traffic jam. The result of this indicated that the mean concentration of CO, NO 2 and SO 2 emission at Kabuga, Kofar ruwa, Hotoro NNPC and Aminu Kano Teaching Hospital traffic junctions, gaseous emissions were within NESREA guideline limit for ambient conditions, except for CO concentration of 14.43 and 13.60 ppm at Bata and Kantin Kwari intersections were found to be much higher when compared with the NESREA guideline limits, respectively. This implies that transport-related pollution around Bata and Kantin Kwari is apparently unsafe. Similarly, it is likely that air quality will continue to deteriorate as the city continues to grow. Therefore, there is need for government to institute and enforce traffic emission control and air quality management programs as a priority. They should also work to prevent further environmental degradation by adopting effective policy in Nigeria.

Household carbon monoxide (CO) concentrations in a large African city: An unquantified public health burden?

Carbon monoxide (CO) is a poisonous gas produced by incomplete combustion of carbon-based fuels that is linked to mortality and morbidity. Household air pollution from burning fuels on poorly ventilated stoves can lead to high concentrations of CO in homes. There are few datasets available on household concentrations of CO in urban areas of sub-Saharan African countries. CO was measured every minute over 24 h in a sample of homes in Nairobi, Kenya. Data on household characteristics were gathered by questionnaire. Metrics of exposure were summarised and analysis of temporal changes in concentration was performed. Continuous 24-h data were available from 138 homes. The mean (SD), median (IQR) and maximum 24-h CO concentration was 4.9 (6.4), 2.8 (1.0–6.3) and 44 ppm, respectively. 50% of homes had detectable CO concentrations for 847 min (14h07m) or longer during the 24-h period, and 9% of homes would have activated a CO-alarm operating to European specifications. An association between a metric of total CO exposure and self-reported exposure to vapours >15 h per week was identified, however this were not statistically significant after adjustment for the multiple comparisons performed. Mean concentrations were broadly similar in homes from a more affluent area and an informal settlement. A model of typical exposure suggests that cooking is likely to be responsible for approximately 60% of the CO exposure of Nairobi schoolchildren. Household CO concentrations are substantial in Nairobi, Kenya, despite most homes using gas or liquid fuels. Concentrations tend to be highest during the evening, probably associated with periods of cooking. Household air pollution from cooking is the main source of CO exposure of Nairobi schoolchildren. The public health impacts of long-term CO exposure in cities in sub-Saharan Africa may be considerable and should be studied further.

Application of Satellite Observation and GIS in Mapping Greenhouse Gases in Part Delta State, Nigeria

The present study aimed to apply satellite observation and Geographic Information System (GIS) to map GHGs in Delta State, Nigeria. Carbon monoxide (CO), nitrous oxide (N O), and sulfur dioxide (SO ) constituted the main GHGs studied. The2 2 datasets covering January 2019 to December 2022 were sourced from the archive of Copernicus Atmosphere Monitoring Service Emissions of Atmospheric Compound and Compilation of Ancillary Data. The Google Earth Engine framework, the inverse distance weighting interpolation algorithm in ArcGIS 10.8 software, and Microsoft Excel were deployed in data analyses. In general, the results showed remarkable seasonal oscillation in the mean concentration of CO, with peak values in January and February, while the lowest mean concentration was observed in October. Higher values of NO were observed2 from November to February and the lowest values in July. July also recorded the highest SO values, with the lowest mean2 observable atmospheric concentrations in August, in addition to remarkable insignificant values in 2020–2022. Besides, the 12 geospatial models (maps) also depicted the spatio-temporal distribution of CO, NO , and SO concentrations from 2019 to2 2 2022 for easy visualization and facilitation of workable policies towards global warming mitigation. The paper recommended the establishment of well-equipped and functional ground-based GHG observatories with early warning systems across the state. This will facilitate real-time GHG monitoring, early warning forecasts, and stimulate scholarship on global warming and climate change.

Indoor Air Pollution from Household Cooking and Associated Health Hazards of Selected Rural Communities of Madhupur Tract in Bangladesh

Indoor air pollution is deemed one of the most severe environmental pollutions that occur mainly due to the inefficient and incomplete combustion of solid cooking fuels, which emits different types of particulate matter (PM2.5, PM10). Therefore, this study was organized in the hilly rural area of Sagordighi of Tangail district in Bangladesh to monitor the atmospheric particulate matters PM2.5, PM10 and CO (carbon monoxide) concentrations from the rural kitchens as well as the possible health hazards due to exposure of the air pollutants. One hundred and thirty air samples were collected from the kitchens by using Airveda air quality monitor and Testo 317-3 - Ambient CO meter to monitor the particulate matter and carbon-monoxide concentrations respectively during cooking and non-cooking time. A survey was also conducted through questionnaire. The concentrations of PM2.5 fluctuated from 112-999 µgm-3 whereas the mean concentration was 401.88±232 µgm-3 during cooking time. On the other hand, PM10 concentration varied from 114-1999 µgm-3 were observed during cooking time with a mean concentration was 523.10±413 µgm-3. The concentration of PM2.5 varied from 32-362 µgm-3 at non-cooking period while the mean value was 81.38±41 µgm-3. The concentration of PM10 ranged between 55-429 µgm-3 at non-cooking period and the mean of PM10 was 109.51±51 µgm-3. The mean concentration of CO during cooking period was 51.52±17 ppm and it varied from 20 ppm to 96.4 ppm. On the contrary, the mean concentration of CO during non-cooking period was 6.60± 6 ppm and it fluctuated from 0 to 40 ppm. The concentration of atmospheric particulate matter showed the highest concentration during cooking time. Contemplation on the measured concentration of particulate matters, these values were greater than concentration found in many European cities and also surpassed the Bangladesh National Ambient Air Quality Standard. The monitored CO value exceeded the recommended value. Questionnaire survey result indicated that respondents suffered from various diseases due to household cooking activities such as facing eye irritation, headaches, dry cough, dizziness and nasal congestion during cooking time. This research suggests installation of improved cooking stoves and providing proper ventilation facilities in kitchen and using renewable energy as well as creating public awareness among rural communities for minimizing the impacts of pollutants emitted from cooking activities.

Temporal assessment of air quality in major cities in Nigeria using satellite data

This study evaluated the concentrations of tropospheric nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and Aerosol Index (AI) as well as different meteorological parameters, including atmospheric temperature (AT), relative humidity (RH), and wind speed (WS) in nine Nigerian cities: Aba, Benin, Ibadan, Kaduna, Kano, Lagos, Onitsha, Port Harcourt, and Umuahia. The role of socioeconomic activities on air pollution was also investigated using nighttime light radiance as a surrogate measure. Welch's one-way ANOVA test was performed for the variance study to evaluate the concentration dynamics of the selected tropospheric air pollutants and their association with nighttime light radiance. The mean concentration of CO and AI was highest in Kano, while that of O3 was the lowest. A similar pattern was also observed in the spatiotemporal transition of the selected pollutants and the nighttime light during the study period. Further, the correlation analysis revealed that AT is positively correlated with NO2 except in Aba and Benin cities, while it is positively correlated with CO and AI for all cities. The principal component analysis (PCA) revealed that O3 and RH have strong negative factor loadings, whereas CO, AI, and AT have strong positive factor loadings. This study will guide future researchers by associating the level of pollution with socioeconomic activities, especially during the absence of permanent air quality stations.

Prediction of CO pollutant in Mashhad metropolis, Iran: Using multiple linear regression

AbstractGiven the importance of carbon monoxide (CO) in acute health threats, studies have been conducted in different countries and cities (272 cities in China and 337 cities on a global scale) on the relationship between daily mortality and CO while the spatial analysis of factors affecting CO pollutant in cities, especially in developing countries, has rarely been done. Accordingly, this research has measured the effect of five environmental‐social variables (ESVs) on the spatial distribution of CO pollutants in the metropolis of Mashhad, Iran. CO concentration data were collected in 23 air pollutant monitoring stations in an area of 356 km2 in 2019. Then, the relationship between five variables and CO pollutant were measured using linear and multiple regression by Sentinel 2A and 3 satellite images in ArcGIS and TerrSet software. The results show that the mean CO concentration averages at 1.56 ppm in the whole city. But its range varies between 0.171 and 2.907 ppm, which is a low figure compared with presented standards and does not indicate a critical situation. The results of multiple regression indicate that 42% of the variance in CO concentration is explained by independent variables. Among five independent variables, the beta value of the land surface temperature (LST) and digital elevation model (DEM) variables is negative and positive for the other three variables, including population density, normalised difference vegetation index (NDVI) and normalised difference built‐up index (NDBI). It should be noted that the strongest correlating variable is population density. Prediction of the spatial distribution of CO pollutants shows the division of the city into three areas: (1) the south and southwest slopes of the city with a low concentration; (2) central areas with a medium concentration; and (3) northern and northeastern areas of the city with a high concentration where low‐income groups reside and there are more worn‐out vehicles, motorcycles and industrial workshops. Areas with high CO concentration need more attention from urban managers.

Ambient carbon monoxide and cardiovascular-related hospital admissions: A time-series analysis.

Background and aims: Although several studies have investigated the association between air pollutants and cardiovascular diseases (CVDs) in recent years, a lack of evidence exists regarding carbon monoxide (CO) exposure, especially in the Eastern Mediterranean's polluted regions. In this study, we aimed to evaluate the short-term effect of CO exposure on daily CVD hospital admissions in Isfahan, a major city in Iran. Methods: Data were extracted from the CAPACITY study on daily CVD hospital admissions in Isfahan from March 2010 to March 2012. The 24-h mean CO concentrations were obtained from four local monitoring stations. In a time-series framework, the association between CO and daily hospitalizations for total and cause-specific CVDs in adults (ischemic heart disease (IHD), heart failure (HF), and cerebrovascular disease) was conducted using Poisson's (or negative binomial) regression, after adjusting for holidays, temperature, dew point, and wind speed, considering different lags and mean lags of CO. The robustness of the results was examined via two- and multiple-pollutant models. Stratified analysis was also conducted for age groups (18-64 and ≥65years), sex, and seasons (cold and warm). Results: The current study incorporated a total of 24,335 hospitalized patients, (51.6%) male with a mean age of 61.9 ± 16.4 years. The mean CO concentration was 4.5 ± 2.3mg/m³. For a 1mg/m3 increase in CO, we found a significant association with the number of CVD hospitalizations. The largest adjusted percent change in HF cases was seen in lag0, 4.61% (2.23, 7.05), while that for total CVDs, IHD, and cerebrovascular diseases occurred in mean lag2-5, 2.31% (1.42, 3.22), 2.23% (1.04, 3.43), and 5.70% (3.59, 7.85), respectively. Results were found to be robust in two- and multiple-pollutant models. Although the associations changed for sex, age groups, and seasons, they remained significant for IHD and total CVD, except for the warm season, and for HF, except for the younger age group and cold seasons. Additionally, the exposure-response relationship curve of the CO concentrations with total and cause-specific CVD admissions showed non-linear relationships for IHD and total CVDs. Conclusions: Our results showed that exposure to CO contributed to an increase in the number of CVD hospitalizations. The associations were not independent of age groups, season, and sex.

Study on the Impact of Firecrackers on Atmospheric Pollutants during Diwali Festival in Tamil Nadu, India

The current study focuses on the impact of firecrackers emission on particulate matter (PM2.5 and PM10), carbon monoxide (CO), carbon dioxide (CO2), and total volatile organic compounds (TVOC) and the noise was analyzed on pre, during, and post-Diwali 2022 period (5 days) in a residential area of Tamil Nadu state of India. The findings demonstrated that, for 24-hour mean values of PM2.5 and PM10 concentrations over the study period were consistently higher than the NAAQS (National Ambient Air Quality Standard) permitted limit. On the day of Diwali, the mean CO concentration reaches 2.5 mg/m3, exceeding the NAAQSrecommended allowable limit of 2 mg/m3. The CO2 concentration during Diwali day is 1.8 times higher than the pre-Diwali day. In addition, the 24-hour mean concentration of TVOC during pre-Diwali, Diwali, and post-Diwali was found to be 915.21 µg/m³, 1513.52 µg/m³ and 1617.12 µg/m³ respectively which is quite higher than normal days. Furthermore, the average noise level in the study site during pre, during, and post-Diwali was found to be 57.71 dB (A), 75.5 dB (A), and 63.66 dB (A) respectively which were higher than the safer limit on the residential zone. As a result of the widespread usage of firecrackers during Diwali festivities, these pollutants are significantly increased, which may have a negative influence on the general public’s health.

Carbon monoxide profile variability over the Manaus Metropolitan Region and its relations with biomass burning

The present study analyzes the temporal variability of carbon monoxide (CO) over the Manaus Metropolitan Region (MMR) and its relations with nearby fires based on data obtained by the environmental satellite AQUA, for the 2003–2020 period. For this purpose, wavelet transform analyses and wavelet coherence analyses were used. The results show a well-defined seasonal behavior, with an increase and decrease in mean CO concentrations during dry and wet seasons, respectively. Semiannual and annual scales represent around 95 % of CO temporal variability in lower troposphere (500 to 1,000 hPa) and are associated with rains and fires dynamics in the region. In terms of interannual variability, multiple variability scales (1.2–2, 2.5–3 and 4.5–6 years) were observed, which explain around 10–15 % of concentration variability near surface. The results suggest that climatic variations, associated with the tropical Pacific and Atlantic sea surface temperature variations, on these different time scales, affect rain dynamics and, consequently, fires and CO concentration. Specifically, in 2015/16, the combined effect from different variability scales acted to prolong the dry period over the region, which contributed to increase fires and the CO to reach higher values compared to previous years. These results show a new aspect of the importance of evaluating the combined effect of different climate variability scales on CO concentrations in the atmosphere.

Gaseous Air Pollutants and Respirable Crystalline Silica Inside and Outside Homes at Brick Kilns in Bhaktapur, Kathmandu Valley, Nepal.

Household and ambient air pollution remain public health problems in much of the world. Brick kiln employees in Nepal may be particularly at risk of high air pollution exposures and resulting health effects due to high levels of outdoor air pollution, substandard housing, and indoor biomass cooking. We conducted a cross-sectional study of indoor and outdoor air pollution concentrations at workers’ homes at four fixed chimney Bull’s trench brick kilns in Bhaktapur, Kathmandu Valley, Nepal. We measured air concentrations of carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), sulfur dioxide (SO2), and respirable crystalline silica (SiO2; cristobalite, quartz, tridymite) using established methods and conducted a survey about characteristics of homes or samples that may be associated with air pollution concentrations. Geometric mean concentrations of CO, CO2, and SiO2 (quartz) were 0.84 ppm, 1447.34 ppm, and 6.22 µg/m3, respectively, whereas concentrations of all other air pollutants measured below lower detection limits. Most characteristics of homes or samples were not associated with air pollution concentrations. We found a positive association between the variable how long lived in house and SiO2 (quartz) concentrations, which may reflect sustained take-home exposure to SiO2 (quartz) over time. Interventions should focus on administrative controls to reduce take-home exposure to SiO2 (quartz) in this population.

Long-term trends and affecting factors in the concentrations of criteria air pollutants in South Korea

Here, we used a novel approach to analyze the trends in the concentrations of six national criteria air pollutants, carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), PM10, PM2.5, and surface ozone (O3), between 2001 and 2018, and the factors affecting the concentrations of CO and SO2 at the district level in South Korea (Korea) between 2011 and 2016. We considered four factors affecting the concentrations of CO and SO2: (1) concentration-to-emission ratio, (2) air pollutant-to-CO2 emission ratio, (3) carbon intensity, and (4) area-weighted energy supply. We found that the most influencing factors determining the concentrations of CO and SO2in Korea were the air pollutant-to-CO2emission ratio and the concentration-to-emission ratio. The annual mean concentrations of CO, SO2, PM10, PM2.5, and NO2 generally decreased, while O3 levels showed an increasing trend, over the last 18 years in Korea. We also found that NO2 concentration had strong positive and negative correlations with PM2.5 and O3 concentrations, respectively. However, the relationship between O3 and NO2 levels showed an inverted U shape under NO2 super-rich condition (e.g., > 55ppb in Seoul), and the daily maximum 8-h values (MDA8O3) increased in proportion to the NO2 level under poor NO2 conditions (e.g., < 25ppb in Seoul).

Indoor Air Pollution in Rumuewhera Community in Obio-Akpor Local Government Area of Rivers State, Nigeria

Indoor air pollution arising from the use of biomass fuel for cooking is a serious health issue in Nigeria especially in rural communities. This study investigated the levels of Carbon monoxide (CO), PM2.5 and PM10 released during morning and evening cooking sessions in 17 households in Rumuewhara community in Obio/Akpor LGA, Rivers State Nigeria. This was to ascertain indoor air pollution concentrations in rural households categorized in the terms of fuel type (Firewood, Kerosene and LPG) and kitchen configuration. In the morning cooking session, mean and standard deviation of CO, PM2.5 and PM10 concentration levels from households using LPG (8.78 + 5.20 ppm, 25.5 + 6.65 µg/m3 and 39.38 + 13.28 µg/m3) were observed as lower than those from other households using biomass fuels (36.78 + 19.44 ppm, 270.16 + 159.44 µg/m3 and 419.82 + 247.29 µg/m3 for firewood). The mean concentrations of CO, PM2.5 and PM10 during cooking sessions in firewood kitchens are clearly higher than the standard limits of WHO and Health Canada due to the fuel type, kitchen configuration and ventilation habit. With correlation coefficients, r = -0.537, P=.03; r = -0.583, P=.01 and r = -0.566, p=0.02; there is a statistically significant and strong negative correlation between Relative Humidity vs CO, PM2.5 and PM10 respectively. The use of biomass fuels for household cooking should be discouraged in favour of LPG or kerosene due to the high concentration of indoor air pollutants it generates. To reduce the effects of biomass fuels, well-positioned Chimneys should be incorporated into houses to limit the accumulation of indoor air pollutants in the cooking area.

Understanding Off-Gassing of Biofuel Wood Pellets Using Pellets Produced from Pure Microcrystalline Cellulose with Different Additive Oils

Fuel wood pellets have the tendency of undergoing self-heating and off-gassing during storage and transportation. Self-heating can lead to spontaneous combustion and cause fires while toxic gasses such as carbon monoxide and some volatile organic compounds released due to off-gassing are a human health and environmental hazard. Previous research suggests that the self-heating and off-gassing of wood pellets are as a result of the oxidation of wood extractives. The aim of this study was to identify the extractives, i.e., fatty and resin acids that are responsible for the emissions of carbon monoxide, carbon dioxide and methane from wood pellets by testing the off-gassing tendencies of pellets produced from synthetic microcrystalline cellulose and different additive oils. The additive oils were intentionally selected to represent different types of wood extractives (mainly fatty and resin acids) and they included: tall oil, pine rosin, linseed oil and coconut oil. The highest mean concentrations of carbon monoxide, carbon dioxide and methane were recorded from cellulose pellets with added linseed oil. The concentrations of carbon monoxide and methane for the other four pellet types were negligible and there was no carbon dioxide emission. Pellets with added linseed oil had high off-gas emissions due to the high content of unsaturated fatty acids compared to other pellet types.

Carbon monoxide exposures in wildland firefighters in the United States and targets for exposure reduction.

Background:Every year thousands of wildland firefighters (WFFs) work to suppress wildfires to protect public safety, health, and property. Although much effort has been put toward mitigating air pollutant exposures for the public and WFFs, the current burden in this worker population is unclear as are the most effective exposure reduction strategies.Objective:Quantify fireline carbon monoxide (CO) exposures in WFFs and identify predictors of exposures.Methods:We collected one-minute breathing zone CO measurements on 246 WFFs assigned to fires between 2015 and 2017. We used generalized estimating equations to evaluate predictors of CO exposure.Results:Approximately 5 percent of WFFs had fireline CO exposure means exceeding the National Wildfire Coordinating Group’s (NWCG) occupational exposure limit of 16 ppm. Relative to operational breaks, direct suppression-related job tasks were associated with 56% (95% CI: 47%, 65%) higher geometric mean CO concentrations, adjusted for incident type, crew type, and fire location. WFF perception of smoke exposure was a strong predictor of measured CO exposure.Significance:Specific job tasks related to direct suppression and WFF perceptions of smoke exposure are potential opportunities for targeted interventions aimed at minimizing exposure to smoke.

Relationship between air pollution levels in Madrid and the natural history of idiopathic pulmonary fibrosis: severity and mortality

ObjectiveWe aimed to assess the relationship between major air pollutants and the natural history and mortality of idiopathic pulmonary fibrosis (IPF).MethodsWe conducted a retrospective cohort study from 2013 to 2019 among 52 patients with IPF from the pneumology department of a tertiary hospital. According to their geocoded residential address, each patient was assigned a mean concentration of carbon monoxide (CO), nitrogen dioxide, particulate matter 2.5 and 10, ozone, and sulfur dioxide, as measured at a single surveillance station in central Madrid, Spain. We analyzed forced vital capacity (FVC), CO diffusing capacity, 6-minute walking test, degree of dyspnea, radiologic pattern, and signs of pulmonary hypertension in all patients.ResultsPatients’ mean age was 66 ± 10 years, and 79% were men. The mean predicted FVC was 78.9 ± 0.5%. Forty-two patients met the criteria for severe disease, and 18 patients died. Mortality was significantly associated with increased CO exposure (for each 0.1 mg/m2 increase: odds ratio 2.45, 95% confidence interval 1.39–4.56). We observed no association between any of the other investigated contaminants and IPF mortality or severity.ConclusionsAir pollution, specifically that caused by carbon monoxide, can increase mortality in patients with IPF.

Assessment of Indoor Air Quality and Health Impact associated with the use of Different Types of Cooking Stoves amongst Rural Households in Kwara State, Nigeria

The study focused on assessing the health impact of indoor air pollution and coping strategies adopted among rural households in Kwara state, Nigeria. A three-stage random sampling techniques was used to select 150 household respondents. The data for the study were collected using a well-structured questionnaire and an MSA gas-detector used to monitor the concentration of Carbon-monoxide (CO), Sulphur-dioxide (SO2) and Hydrogensulphide (H2S) pollutants. Descriptive and inferential statistics were employed to analyze the data. However, the result revealed that the mean concentration of CO, SO2 and H2S in the kitchen during cooking were 77.20, 1.97 and 0.25 parts-per millions (ppm) respectively. The World Health recommends exposure limits of 35ppm for 1hour and 9ppm for 8hours for CO concentration in a household. While, the recommended exposure limits of 0.5ppm and 1.0ppm for 8 hours, and 5.0ppm and 10.0ppm for 15minutes for SO2 and H2S concentrations in a household respectively. Eye irritation, Sneezing and headache were the 1st, 2nd and 3rd perceived health problems found to be associated with indoor air pollution. Also, the Pearson χ2 result (15.051, 15.454, and 11.853 with P&lt;0.05) revealed that cold/catarrh/cough, headache/fever, and body pain ailments respectively have significant association with types of cooking stove used by rural households. Thus, inefficient wood and charcoal stoves influence rural household health negatively and they cope by adopting indigenous management practices.&#x0D; Keywords: Pollution, concentration, irritation, stove, ailments

Effect of Cooking Fuel Choice on the Typology of Indoor Pollutants in Port Harcourt Metropolis: Implications for the incidence of Sick Building Syndrome

The study examined the effect of cooking fuel choice on indoor air quality and its implication for the incidence of sick building syndrome in different residential land use areas of Port Harcourt metropolis. Questionnaire survey and measurement of indoor air pollutants in residential areas were undertaken. The residential areas were stratified into high, middle and low income residential land use. Purposive sampling and random sampling techniques were used to select two residential areas and two streets from each selected residential land use. The questionnaire survey exercise that features respondents’ types of cooking fuel choices were accessed by given identification numbers to buildings. The odd numbers were enumerated for each area (residential land use). Based on consent and approval, 15 residential buildings (5 from each residential area) were selected for air quality measurements. Composite sampling technique was deployed for the collection of air quality data from the 15 households at a distance of 2m away from source of cooking fuel. The air quality parameters measured were Carbon dioxide (CO2 ), Carbon monoxide (CO), Nitrogen dioxide (NO2 ), Sulphur dioxide (SO2 ), Nitrogen oxide (NO), Nitrogen IV oxide (NO2 ) and Particulate matter (PM2.5). Both Descriptive statistics and Inferential statistics were deployed (Spearman Rank Correlation and ANOVA. Findings revealed that LP Gas (38.6%) was mostly used by residents. The concentration of gaseous pollutants of CO, CO2 , SO2 , NO and PM2.5 were all highest under low income residential area with mean concentrations of CO, =3.56(mg/m3 ), CO2 =539.5(mg/m3 ), SO2 =1.48(mg/m3 ), NO= 0.72 (mg/m3 ), and PM2.5=16.4 ug/mg3 respectively; except NO2 with concentration of 1.02 mg/m3 during the morning cooking periods. Findings revealed that measured air quality especially in the low income residential area failed to meet the perfect conditions of fresh air due to the heavy use of firewood, kerosene and charcoal as choice of cooking fuel. Thus, cooking fuel choice has direct effect on indoor air quality and the risk of Sick Building Syndrome. The study recommends that choices for cooking fuel should not be based on cost but on low health implications as this will help reduce the associated health risk factors of indoor air pollution in the study area.

Air Pollutants Exposure and the Occurrence of Respiratory Diseases among Residents of Ogbomoso Metropolis

Background/Aim: Air pollution is a major environmental threat and a risk factor for both acute and chronic respiratory diseases. The current surge in the cases of chronic diseases require an investigation of environmental contributors. This study examined the association between air pollutants and respiratory diseases occurrence in Ogbomoso Metropolis, Nigeria. Methods: The concentrations of Carbon dioxide (CO2), Sulphur dioxide (SO2), Carbon monoxide (CO), Hydrogen sulphide (H2S), Volatile organic compounds (VOCs), particulate matter (PM2.5, PM10) and meteorological parameters (relative humidity, temperature, pressure, wind speed and direction) were measured using Aeroqual gas meter and Windmate respectively at eighty locations in the study area. Information on recorded cases of respiratory health problems were obtained from a State hospital in the study area. Results: The concentrations of CO2, SO2, CO, H2S, VOC, PM2.5 and PM10 ranged between 2351±127.1 and 1435±439; 0.7417±0.6554 and 0.1375±0.1245; 45.79±50.48 and 17.67±21.62; 0.7±0.4075 and 0.2833±0.0916; 149±135.1 and 39.83±19.26; 151.5±188.9 and 27.79±5.618; 576.7±943.4 and 109.8±31.98 μg/m3 respectively. Mean concentrations of CO (17- 45 μg/m3), PM2.5 (27-151 μg/m3) and PM10 (109-576 μg/m3) were significantly higher than the WHO permissible limits while others were below the allowable limits. There are significant variations (p&lt;0.05) in the concentrations of all the sampled gases and meteorological parameters in the various locations. Respiratory health problems reported to hospitals between 2015-2019 included upper respiratory tract infection (42.13%), respiratory tract infection (35.56%) and cough (6.25%) among others out of 1600 cases. Conclusion: As demonstrated by the findings of this study, exposure to air pollutants contribute significantly to occurrence of respiratory diseases.

The effects of ventilation and building characteristics on indoor air quality in waterpipe cafés.

To determine the concentration of carbon monoxide (CO) and particulate matter (PMs), indoor air samples were collected from 60 waterpipe cafés in Ardabil city of Iran. Moreover, the influence of several structural, operational, and ventilation system were evaluated on the concentration of the selected pollutants. The results showed that the mean concentration of CO (12.0 ± 7.2 mg/m3) and PMs (PM1 = 171.5 ± 119.6 μg/m3, PM2.5 = 303.3 ± 201.9 μg/m3, PM10 = 440.3 ± 272.2 μg/m3) were notably higher than the guideline levels. According to the results, open face/café area was influenced by the natural ventilation rate and the mean air exchange rate was 3.1 ± 1.1 min-1. The natural ventilation has a functional role on air quality of the cafes, and fan-type mechanical ventilation was influencing factor on CO concentration when the natural ventilation was restricted. "Type of used charcoal" had the highest influence on the releasing of pollutants inside the cafés as the pollutant concentrations were lower for simple (raw) charcoal compared with the favored (aromatic) one. The results indicated that the building characteristics and natural ventilation considerably affect air quality of the cafes.

Carbon monoxide: a critical physiological regulator sensitive to light

The mechanism by which humans absorb therapeutic light in winter seasonal and nonseasonal depression is unknown. Bright-light-induced release and generation of blood-borne gasotransmitters such as carbon monoxide (CO) may be one mechanism. Here, 24 healthy female volunteers had peripheral blood samples drawn. Samples were collected in a dimly lit room and protected from light exposure. Samples were analyzed for CO concentrations by gas chromatography after 2 h of continuous exposure to darkness vs. bright white light. In a similar confirmatory study, 11 additional volunteers had samples analyzed for CO concentrations after 2 h of continuous exposure to gentle rocking in darkness vs. in bright white light. In the first study, light-unexposed peripheral blood had a mean CO concentration of 1.8 ± 0.4 SD ppm/g. Identically treated samples with 2 h of rocking and exposure to bright white light at illuminance 10,000 lux had a mean CO of 3.6 ± 1.2 ppm/g (p < 0.0001). Post hoc analysis of that study showed that time of day was significantly inversely associated with increase in CO concentration under bright light vs. dark (p < 0.04). In a smaller confirmatory study of 11 healthy female volunteers, after 2 h of rocking, light-unexposed peripheral blood had a mean CO of 1.4 ± 0.5 SD ppm/g. Identically treated blood samples with 2 h of exposure to bright white light at illuminance 10,000 lux had a mean CO of 2.8 ± 1.7 ppm/g (p < 0.02). In conclusion, bright-light exposure robustly increases human blood CO in vitro. This supports the putative role of CO as a physiological regulator of circadian rhythms and light’s antidepressant effects. This human evidence replicates earlier data from a preclinical in vivo model. This effect may be stronger in the morning than in the afternoon.