Displaying publications 261 - 280 of 478 in total

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  1. Fulltext Pulmonary overinflation syndrome in an underwater logger
    Rozali A, Sulaiman A, Zin BM, Khairuddin H, Abd-Halim M, Mohd Sidik S
    Med J Malaysia, 2006 Oct;61(4):496-8.
    PMID: 17243532 MyJurnal
    Pulmonary overinflation syndrome (POIS) is a group of barotrauma-related diseases caused by the expansion of gas trapped in the lung, or over-pressurization of the lung with subsequent over-expansion and rupture of the alveolar air sacs. This group of disorders includes arterial gas embolism, tension pneumothorax, mediastinal emphysema, subcutaneous emphysema and rarely pneumopericardium. In the case of diving activities, POIS is rarely reported and is frequently related to unsafe diving techniques. We report a classical case of POIS in an underwater logger while cutting trees for logs in Tasik Kenyir, Terengganu. The patient, a 24-year-old worker, made a rapid free ascent to the surface after his breathing equipment malfunctioned while he was working underwater. He suffered from bilateral tension pneumothoraces, arterial gas embolism giving rise to multiple cerebral and cerebellar infarcts, mediastinal and subcutaneous emphysema as well as pneumopericardium. He was treated in a recompression chamber with hyperbaric oxygen therapy and discharged with residual weakness in his right leg.
    Matched MeSH terms: Embolism, Air/diagnosis; Embolism, Air/etiology*
  2. Performance assessment of the Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation II score, and the Sequential Organ Failure Assessment score in predicting the outcomes of adult patients with hepatic portal venous gas in the ED
    Seak CJ, Ng CJ, Yen DH, Wong YC, Hsu KH, Seak JC, et al.
    Am J Emerg Med, 2014 Dec;32(12):1481-4.
    PMID: 25308825 DOI: 10.1016/j.ajem.2014.09.011
    This study aims to evaluate the performance of Simplified Acute Physiology Score II (SAPS II), the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and the Sequential Organ Failure Assessment (SOFA) score for predicting illness severity and the mortality of adult hepatic portal venous gas (HPVG) patients presenting to the emergency department (ED). This will assist emergency physicians in risk stratification.
    Matched MeSH terms: Embolism, Air/diagnosis*; Embolism, Air/mortality
  3. Start-up, performance and optimization of a compost biofilter treating gas-phase mixture of benzene and toluene
    Rene ER, Kar S, Krishnan J, Pakshirajan K, López ME, Murthy DV, et al.
    Bioresour Technol, 2015 Aug;190:529-35.
    PMID: 25827361 DOI: 10.1016/j.biortech.2015.03.049
    The performance of a compost biofilter inoculated with mixed microbial consortium was optimized for treating a gas-phase mixture of benzene and toluene. The biofilter was acclimated to these VOCs for a period of ∼18d. The effects of concentration and flow rate on the removal efficiency (RE) and elimination capacity (EC) were investigated by varying the inlet concentration of benzene (0.12-0.95g/m(3)), toluene (0.14-1.48g/m(3)) and gas-flow rate (0.024-0.072m(3)/h). At comparable loading rates, benzene removal in the mixture was reduced in the range of 6.6-41% in comparison with the individual benzene degradation. Toluene removal in mixture was even more affected as observed from the reductions in REs, ranging from 18.4% to 76%. The results were statistically interpreted by performing an analysis of variance (ANOVA) to elucidate the main and interaction effects.
    Matched MeSH terms: Air Pollutants/isolation & purification*; Air Pollutants/chemistry
  4. Sick building syndrome (SBS) among office workers in a Malaysian university--Associations with atopy, fractional exhaled nitric oxide (FeNO) and the office environment
    Lim FL, Hashim Z, Md Said S, Than LT, Hashim JH, Norbäck D
    Sci Total Environ, 2015 Dec 1;536:353-61.
    PMID: 26225741 DOI: 10.1016/j.scitotenv.2015.06.137
    There are few studies on sick building syndrome (SBS) including clinical measurements for atopy and fractional exhaled nitric oxide (FeNO). Our aim was to study associations between SBS symptoms, selected personal factors, office characteristics and indoor office exposures among office workers from a university in Malaysia. Health data were collected by a questionnaire (n=695), skin prick test (SPT) (n=463) and FeNO test (n=460). Office settled dust was vacuumed and analyzed for endotoxin, (1,3)-β-glucan and house dust mites (HDM) allergens group 1 namely Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1). Office indoor temperature, relative air humidity (RH), carbon monoxide (CO) and carbon dioxide (CO2) were measured by a direct reading instrument. Associations were studied by two-levels multiple logistic regression with mutual adjustment and stratified analysis. The prevalence of weekly dermal, mucosal and general symptoms was 11.9%, 16.0% and 23.0% respectively. A combination of SPT positivity (allergy to HDM or cat) and high FeNO level (≥25 ppb) was associated with dermal (p=0.002), mucosal (p<0.001) and general symptoms (p=0.05). Der f1 level in dust was associated with dermal (p<0.001), mucosal (p<0.001) and general (p=0.02) symptoms. Among those with allergy to D. farinae, associations were found between Der f 1 levels in dust and dermal (p=0.003), mucosal (p=0.001) and general symptoms (p=0.007). Office-related symptoms were associated with Der f 1 levels in dust (p=0.02), low relative air humidity (p=0.04) and high office temperature (p=0.05). In conclusion, a combination of allergy to cat or HDM and high FeNO is a risk factor for SBS symptoms. Der f 1 allergen in dust can be a risk factor for SBS in the office environment, particularly among those sensitized to Der f 1 allergen.
    Matched MeSH terms: Air Pollution, Indoor/analysis*; Air Pollution, Indoor/statistics & numerical data
  5. Fractional exhaled nitric oxide (FeNO) among school children in Java and Sumatra, Indonesia: associations with respiratory symptoms, house dust mite sensitization and the home environment
    Norbäck D, Hashim JH, Hashim Z, Jalaludin J, Ismail R, Wieslander G, et al.
    J Asthma, 2024 Dec;61(12):1772-1780.
    PMID: 39066997 DOI: 10.1080/02770903.2024.2383627
    OBJECTIVE: To study associations between fractional exhaled nitric oxide (FeNO) and asthma, airway symptoms, sensitization to common allergens, outdoor pollution and home environment among 380 students in eight junior high schools in two areas in Indonesia.

    METHODS: Data on health and home were collected by a face-to face interview before measuring FeNO and performing skin prick test against common allergens. Exploratory linear mixed and logistic regression models were employed.

    RESULTS: Geometric mean of FeNO was 17.8 ppb (GSD 2.09) and 139 students (36.6%) had elevated FeNO (>20 ppb). In total, 107 students (28.2%) were sensitized to house dust mite (HDM) (Der p1 or Der f1), 4 (1.1%) to cat and 3 (0.8%) to mold (Cladosporium or Alternaria). Moreover, 20 students (5.3%) had diagnosed asthma, 38 (10.0%) had current wheeze, and 107 (28.2%) had current rhinitis. HDM sensitization, diagnosed asthma, current wheeze, and current rhinitis were associated with FeNO. In total, 281 students (73.9%) had mold or dampness, 232 (61.1%) had environmental tobacco smoke (ETS) and 43 (11.3%) had other odor at home. Indoor mold or dampness and other odor at home were associated with FeNO. ETS was negatively associated with FeNO.

    CONCLUSION: HDM sensitization and elevated FeNO can be common among children in this part of Indonesia. The high prevalence of elevated FeNO indicate that undiagnosed childhood asthma is common. Dampness, mold and odor at home can be associated with increased FeNO while ETS can be associated with decreased FeNO.

    Matched MeSH terms: Air Pollution, Indoor/adverse effects; Air Pollution, Indoor/analysis
  6. Optimization of palm oil mill sludge biochar preparation for sulfur dioxide removal
    Iberahim N, Sethupathi S, Bashir MJK
    Environ Sci Pollut Res Int, 2018 Sep;25(26):25702-25714.
    PMID: 28550632 DOI: 10.1007/s11356-017-9180-5
    In this study, palm oil mill sludge was used as a precursor to prepare biochar using conventional pyrolysis. Palm oil mill sludge biochar (POSB) was prepared at different preparation variables, i.e., heating temperature (300-800 °C), heating rate (10-20 °C/min) and holding time (60-120 min). The prepared biochars were tested for sulfur dioxide (SO2) adsorption in a fixed bed reactor using 300 ppm of SO2 gas at 300 ml/min (with N2 gas as balance). Response surface central composite experimental design was used to optimize the production of biochar versus SO2 removal. A quadratic model was developed in order to correlate the effect of variable parameters on the optimum adsorption capacity of SO2 gas. The experimental values and the predicted results of the model were found to show satisfactory agreement. The optimum conditions for biochar preparation to yield the best SO2 removal was found to be at 405 °C of heating temperature, 20 °C/min of heating rate and 88 min of holding time. At these conditions, the average yield of biochar and adsorption capacity for SO2 gas was reported as 54.25 g and 9.75 mg/g, respectively. The structure of biochar and their roles in SO2 adsorption were investigated by surface area, morphology images, infrared spectra, and proximate analysis, respectively. The characterization findings suggested that POSB adsorbs SO2 mainly by the functional groups.
    Matched MeSH terms: Air Pollutants
  7. Fulltext Accounting for black carbon lowers estimates of blue carbon storage services
    Chew ST, Gallagher JB
    Sci Rep, 2018 02 07;8(1):2553.
    PMID: 29416101 DOI: 10.1038/s41598-018-20644-2
    The canopies and roots of seagrass, mangrove, and saltmarsh protect a legacy of buried sedimentary organic carbon from resuspension and remineralisation. This legacy's value, in terms of mitigating anthropogenic emissions of CO2, is based on total organic carbon (TOC) inventories to a depth likely to be disturbed. However, failure to subtract allochthonous recalcitrant carbon overvalues the storage service. Simply put, burial of oxidation-resistant organics formed outside of the ecosystem provides no additional protection from remineralisation. Here, we assess whether black carbon (BC), an allochthonous and recalcitrant form of organic carbon, is contributing to a significant overestimation of blue carbon stocks. To test this supposition, BC and TOC contents were measured in different types of seagrass and mangrove sediment cores across tropical and temperate regimes, with different histories of air pollution and fire together with a reanalysis of published data from a subtropical system. The results suggest current carbon stock estimates are positively biased, particularly for low-organic-content sandy seagrass environs, by 18 ± 3% (±95% confidence interval) and 43 ± 21% (±95% CI) for the temperate and tropical regions respectively. The higher BC fractions appear to originate from atmospheric deposition and substantially enrich the relatively low TOC fraction within these environs.
    Matched MeSH terms: Air Pollution
  8. Physicochemical factors and their potential sources inferred from long-term rainfall measurements at an urban and a remote rural site in tropical areas
    Khan MF, Maulud KNA, Latif MT, Chung JX, Amil N, Alias A, et al.
    Sci Total Environ, 2018 Feb 01;613-614:1401-1416.
    PMID: 29898507 DOI: 10.1016/j.scitotenv.2017.08.025
    Air pollution can be detected through rainwater composition. In this study, long-term measurements (2000-2014) of wet deposition were made to evaluate the physicochemical interaction and the potential sources of pollution due to changes of land use. The rainwater samples were obtained from an urban site in Kuala Lumpur and a highland-rural site in the middle of Peninsular Malaysia. The compositions of rainwater were obtained from the Malaysian Meteorological Department. The results showed that the urban site experienced more acidity in rainwater (avg=277mm, range of 13.8 to 841mm; pH=4.37) than the rural background site (avg=245mm, range of 2.90 to 598mm; pH=4.97) due to higher anthropogenic input of acid precursors. The enrichment factor (EF) analysis showed that at both sites, SO42-, Ca2+ and K+ were less sensitive to seawater but were greatly influenced by soil dust. NH4+ and Ca2+ can neutralise a larger fraction of the available acid ions in the rainwater at the urban and rural background sites. However, acidifying potential was dominant at urban site compared to rural site. Source-receptor relationship via positive matrix factorisation (PMF 5.0) revealed four similar major sources at both sites with a large variation of the contribution proportions. For urban, the major sources influence on the rainwater chemistry were in the order of secondary nitrates and sulfates>ammonium-rich/agricultural farming>soil components>marine sea salt and biomass burning, while at the background site the order was secondary nitrates and sulfates>marine sea salt and biomass burning=soil components>ammonia-rich/agricultural farming. The long-term trend showed that anthropogenic activities and land use changes have greatly altered the rainwater compositions in the urban environment while the seasonality strongly affected the contribution of sources in the background environment.
    Matched MeSH terms: Air Pollution
  9. Fulltext Health risk assessment of pm10 exposure among Malaysian adult population based on physical activity pattern
    Norlen Mohame, Lokman Hakim, S., Thahirahtul Asma Zakaria, Anis Salwa Kamarudin, Ahmad Riadz Mazeli, Sirajuddin Hashim
    Int J Public Health Res, 2017;7(2):814-828.
    MyJurnal
    Introduction: Most health advisories related to outdoor physical activity during haze are general in nature. The advisories normally advise everyone to reduce or limit prolonged exertion or heavy exertion without mentioning the acceptable duration for performing outdoor physical activity causing difficulty for public to decide to stop or cancel a particular outdoor or sport event. The aim of this paper is to determine the acceptable duration for performing outdoor physical activity pattern during haze based on API level.

    Methods: Health risk assessment approach that comprises of hazard identification, exposure assessment, dose-response, and risk characterization steps was used to determine the potential inhaled dose and risk associated with performing the physical activity during haze. We have considered many factors that include time spent for physical activity patterns for Malaysian adult, age and physical intensity-specific inhalation rate (m3/min), and the indoor/outdoor ratio of PM10. A hypothetical exposure scenario of PM10 was created using the breakpoints of PM10 concentration for the calculation of respective API levels during haze.

    Results: The association between physical activity pattern, API level and risk quotient were presented in the form of risk radar diagram. Based on the 50th percentile inhalation rate, all prolonged exertion and heavy exertion should be avoided when API reach >201 (very unhealthy) and >175 (unhealthy) respectively. Below the said API, the duration for performing prolonged exertion and heavy exertion should be reduced according to the API level. When API reaches 140, high intensity physical activity should be limited to < 90 minutes. A football match which requires 90 minutes, should be postponed of cancelled if API > 140. Whereas, for the same API level, prolonged exertion (moderate intensity physical activity) should be limited to 4 hours.

    Conclusions: Reducing the physical activity is an effective strategy to lower the dose of inhaled pollutants and reduce the health risk during poor air quality. Based on the assessment, taking into account the uncertainty of risk assessment methodology, we proposed all prolonged exertion should be avoided when API reach very unhealthy status (>201). Below the said API level, outdoor physical activity should be reduced according to the level of API respectively. The recommendation is not applicable for the sensitive groups. The computed risk radar provide a valuable guide for the public to organize or considering postponing an outdoor event during haze.
    Matched MeSH terms: Air Pollution
  10. Fulltext Indoor plants as a filtration of indoor air pollution: a review
    Mohd Mahathir Suhaimi Shamsuri, Leman, A.M.
    Journal of Occupational Safety and Health, 2015;12(2):41-48.
    MyJurnal
    Indoor pollution increasingly becomes a public concern. These concerns are related to energy efficiency in a
    building. There are various ways in which it can ensure energy conservation can be achieved, including superinsulation
    and reduced fresh air exchange. As a result, indoor air becomes stagnant and odours, thereafter contaminants of air will
    accumulate and will certainly disrupt human health. It is quite difficult to make people comfortable in a building with
    consumption of energy-saving and human health guaranteed. Indoor plants are one of the alternative solutions that
    have been studied since the last three decades. This paper intends to review the abilities of indoor plants to purify air,
    and the ways used by previous researchers to prove that indoor plants can treat the air. In general, it can be stated that
    indoor plants are able to absorb various types of volatile organic compounds (VOCs). An advantage of indoor plants
    to cure air from carcinogen gas is greatly needed for human health. Therefore, studies on indoor plants to neutralize
    the air are gaining attention. Enclosed space or chamber is often used by researchers to test the ability of indoor plants
    absorb gaseous toxins in their study; because it is easy to handle and can quickly determine the absorption rate. In the
    other hand, environmental factors such as temperature, humidity, and light are important to be taken into consideration
    during the study. As a conclusion, it can be stated that the existence of indoor plants in a building is very reasonable,
    because it can give positive impacts on human health and the total energy consumption.
    Matched MeSH terms: Air Pollution, Indoor
  11. Fulltext Community perception on human health effect of the biodiesel as an alternative fuel
    Leman, A.M., Amir Khalid, Dafit Feriyanto, Abdullah, N.H., Abdullah, A.A., Mamat, R.
    Journal of Occupational Safety and Health, 2015;12(1):227-231.
    MyJurnal
    In this research, the biodiesel from WCO is used in order to reduce the exhaust emission and to investigate the
    community perception regarding to the human health. Biodiesel production is conducted using trans-esterification
    process with holding time of 2 hours, temperature of 60 oC and conventional frequency of 20 kHz and then followed
    by washing process with holding time of 1 hours, temperature of 50 oC and the frequency of 5 kHz. Biodiesel can
    reduce exhaust emission of NOx up to 55%, NO gas up to 57%, increase CO gas up to 25% and increase CO2 gas up
    to 43.18% as compared to diesel fuel. In addition, biodiesel is achieve good responds from 35 respondents about the
    biodiesel importance.
    Matched MeSH terms: Air Pollutants
  12. Fulltext Application of remote sensing instruments in air quality monitoring in Malaysia
    Mohd Muzammil Salahuddin, Zulfa Hanan Ashaari
    The Pertanika Journal of Scholarly Research Reviews, 2017;3(1):93-112.
    MyJurnal
    The use of remote sensing in detecting aerosol or air pollution is not widely applied in Malaysia. The large area of coverage provided by remote sensing satellite may well be the solution to the lack of spatial coverage by the local ground air quality monitoring stations. This article discusses the application of remote sensing instruments in air quality monitoring of Malaysia. The remote sensing data is validated using ground truths either from local ground air monitoring stations or the Aerosol Robotic Network (AERONET). The correlation between remote sensing is relatively good with R from 0.5 to 0.9 depending on the satellite used. The correlation is much improved using the mixed effects algorithm applied on MODIS Aerosol Optical Depth (AOD) data. Accuracy of predicted air quality data by remote sensing is generally tested using the Root Mean Squared Error (RMSE) against the ground truths data. Besides the Geographic Information System (GIS) tools are used in manipulating the data from both remote sensing and ground stations so as to produce meaningful results such as spatio-temporal pattern mapping of air pollution. Overall the results showed that the application of remote sensing instruments in air quality monitoring in Malaysia is very useful and can be improved further.
    Matched MeSH terms: Air Pollution
  13. Fulltext Fine Particle Emissions From Tropical Peat Fires Decrease Rapidly With Time Since Ignition
    Roulston C, Paton-Walsh C, Smith TEL, Guérette ÉA, Evers S, Yule CM, et al.
    J Geophys Res Atmos, 2018 May 27;123(10):5607-5617.
    PMID: 30167349 DOI: 10.1029/2017JD027827
    Southeast Asia experiences frequent fires in fuel-rich tropical peatlands, leading to extreme episodes of regional haze with high concentrations of fine particulate matter (PM2.5) impacting human health. In a study published recently, the first field measurements of PM2.5 emission factors for tropical peat fires showed larger emissions than from other fuel types. Here we report even higher PM2.5 emission factors, measured at newly ignited peat fires in Malaysia, suggesting that current estimates of fine particulate emissions from peat fires may be underestimated by a factor of 3 or more. In addition, we use both field and laboratory measurements of burning peat to provide the first mechanistic explanation for the high variability in PM2.5 emission factors, demonstrating that buildup of a surface ash layer causes the emissions of PM2.5 to decrease as the peat fire progresses. This finding implies that peat fires are more hazardous (in terms of aerosol emissions) when first ignited than when still burning many days later. Varying emission factors for PM2.5 also have implications for our ability to correctly model the climate and air quality impacts downwind of the peat fires. For modelers able to implement a time-varying emission factor, we recommend an emission factor for PM2.5 from newly ignited tropical peat fires of 58 g of PM2.5 per kilogram of dry fuel consumed (g/kg), reducing exponentially at a rate of 9%/day. If the age of the fire is unknown or only a single value may be used, we recommend an average value of 24 g/kg.
    Matched MeSH terms: Air Pollution
  14. Fulltext Calibration Model of a Low-Cost Air Quality Sensor Using an Adaptive Neuro-Fuzzy Inference System
    Alhasa KM, Mohd Nadzir MS, Olalekan P, Latif MT, Yusup Y, Iqbal Faruque MR, et al.
    Sensors (Basel), 2018 Dec 11;18(12).
    PMID: 30544953 DOI: 10.3390/s18124380
    Conventional air quality monitoring systems, such as gas analysers, are commonly used in many developed and developing countries to monitor air quality. However, these techniques have high costs associated with both installation and maintenance. One possible solution to complement these techniques is the application of low-cost air quality sensors (LAQSs), which have the potential to give higher spatial and temporal data of gas pollutants with high precision and accuracy. In this paper, we present DiracSense, a custom-made LAQS that monitors the gas pollutants ozone (O₃), nitrogen dioxide (NO₂), and carbon monoxide (CO). The aim of this study is to investigate its performance based on laboratory calibration and field experiments. Several model calibrations were developed to improve the accuracy and performance of the LAQS. Laboratory calibrations were carried out to determine the zero offset and sensitivities of each sensor. The results showed that the sensor performed with a highly linear correlation with the reference instrument with a response-time range from 0.5 to 1.7 min. The performance of several calibration models including a calibrated simple equation and supervised learning algorithms (adaptive neuro-fuzzy inference system or ANFIS and the multilayer feed-forward perceptron or MLP) were compared. The field calibration focused on O₃ measurements due to the lack of a reference instrument for CO and NO₂. Combinations of inputs were evaluated during the development of the supervised learning algorithm. The validation results demonstrated that the ANFIS model with four inputs (WE OX, AE OX, T, and NO₂) had the lowest error in terms of statistical performance and the highest correlation coefficients with respect to the reference instrument (0.8 < r < 0.95). These results suggest that the ANFIS model is promising as a calibration tool since it has the capability to improve the accuracy and performance of the low-cost electrochemical sensor.
    Matched MeSH terms: Air Pollution
  15. Pm2.5 and associated ionic species in a sub-urban coastal area of Kuala Terengganu, Southern South China Sea (Malaysia)
    Norhayati Mohd Tahir, Meikee Koh, Suhaimi Suratman
    Sains Malaysiana, 2013;42:1065-1072.
    PM2.5 mass concentration and associated water-soluble ionic species in a sub-urban coastal area of Kuala Terengganu, Malaysia were investigated intermittently from year 2006 to 2009. A total of 78 weekly PM2.5 samples were analyzed. The mass concentration of PM2.5 exhibited annual, seasonal and diurnal variations. Temporal distributions of rainfall, sporadic haze episodes and local air flow (sea breeze circulation) were factors controlling PM2.5 mass variations in the study area. Although the PM2.5 concentrations were increased during haze episodes in 2006 (August and October) and2007 (October), their concentrations however, were still within the international guidelines. The average concentration of individual ions was in decreasing trend; SO42-> NH4+> K+> Na+> NO3-> Cl-> Ca2+. The concentrations of SO42- and NH4+ accounted for > 70% of the water-soluble aerosol mass. More than 80% of ionic species associated with PM2.5 are from non-marine sources. Major processes affecting the ionic composition of PM2.5 are biomass burning, crustal loading and sea spray. Air quality mitigation strategies should focus on anthropogenic activities emitting SO2, which promotes aerosol SO42- formation.
    Matched MeSH terms: Air Pollution
  16. Fulltext Data on Indoor Air Quality (IAQ) in kindergartens with different surrounding activities
    Abdullah S, Abd Hamid FF, Ismail M, Ahmed AN, Wan Mansor WN
    Data Brief, 2019 Aug;25:103969.
    PMID: 31198825 DOI: 10.1016/j.dib.2019.103969
    The aim of the measurement of this data is to evaluate the Indoor Air Quality (IAQ) in terms of chemical and physical parameters. Data were collected at three different kindergartens having different surrounding activities (industrial, institutional, residential area). The chemical parameters measured were respirable suspended particulates of PM10, PM2.5, PM1, carbon monoxide and carbon dioxide, and the concentrations are within the acceptable limit. Physical parameters of wind speed are within the standard, while temperature and relative humidity exceeded the acceptable limit. A strong correlation was found between the chemical IAQ parameters with thermal comfort parameters (temperature and relative humidity). The concentration of IAQ pollutants is higher in order of residential > institutional > industrial.
    Matched MeSH terms: Air Pollution, Indoor
  17. Mapping the cumulative impacts of long-term mining disturbance and progressive rehabilitation on ecosystem services
    Wang Z, Lechner AM, Yang Y, Baumgartl T, Wu J
    Sci Total Environ, 2020 May 15;717:137214.
    PMID: 32062237 DOI: 10.1016/j.scitotenv.2020.137214
    Open-cut coal mining can seriously disturb and reshape natural landscapes which results in a range of impacts on local ecosystems and the services they provide. To address the negative impacts of disturbance, progressive rehabilitation is commonly advocated. However, there is little research focusing on how these impacts affect ecosystem services within mine sites and changes over time. The aim of this study was to assess the cumulative impacts of mining disturbance and rehabilitation on ecosystem services through mapping and quantifying changes at multiple spatial and temporal scales. Four ecosystem services including carbon sequestration, air quality regulation, soil conservation and water yield were assessed in 1989, 1997, 2005 and 2013. Disturbance and rehabilitation was mapped using LandTrendr algorithm with Landsat. We mapped spatial patterns and pixel values for each ecosystem service with corresponding model and the landscape changes were analyzed with landscape metrics. In addition, we assessed synergies and trade-offs using Spearman's correlation coefficient for different landscape classes and scales. The results showed that carbon sequestration, air quality regulation and water yield services were both positively and negatively affected by vegetation cover changes due to mined land disturbance and rehabilitation, while soil conservation service were mainly influenced by topographic changes. There were strong interactions between carbon sequestration, air quality regulation and water yield, which were steady among different spatial scales and landscape types. Soil conservation correlations were weak and changed substantially due to differences of spatial scales and landscape types. Although there are limitations associated with data accessibility, this study provides a new research method for mapping impacts of mining on ecosystem services, which offer spatially explicit information for decision-makers and environmental regulators to carry out feasible policies, balancing mining development with ecosystem services provision.
    Matched MeSH terms: Air Pollution
  18. Fulltext Design, Construction and Testing of IoT Based Automated Indoor Vertical Hydroponics Farming Test-Bed in Qatar
    Chowdhury MEH, Khandakar A, Ahmed S, Al-Khuzaei F, Hamdalla J, Haque F, et al.
    Sensors (Basel), 2020 Oct 02;20(19).
    PMID: 33023097 DOI: 10.3390/s20195637
    Growing plants in the gulf region can be challenging as it is mostly desert, and the climate is dry. A few species of plants have the capability to grow in such a climate. However, those plants are not suitable as a food source. The aim of this work is to design and construct an indoor automatic vertical hydroponic system that does not depend on the outside climate. The designed system is capable to grow common type of crops that can be used as a food source inside homes without the need of large space. The design of the system was made after studying different types of vertical hydroponic systems in terms of price, power consumption and suitability to be built as an indoor automated system. A microcontroller was working as a brain of the system, which communicates with different types of sensors to control all the system parameters and to minimize the human intervention. An open internet of things (IoT) platform was used to store and display the system parameters and graphical interface for remote access. The designed system is capable of maintaining healthy growing parameters for the plants with minimal input from the user. The functionality of the overall system was confirmed by evaluating the response from individual system components and monitoring them in the IoT platform. The system was consuming 120.59 and 230.59 kWh respectively without and with air conditioning control during peak summer, which is equivalent to the system running cost of 13.26 and 25.36 Qatari Riyal (QAR) respectively. This system was circulating around 104 k gallons of nutrient solution monthly however, only 8-10 L water was consumed by the system. This system offers real-time notifications to alert the hydroponic system user when the conditions are not favorable. So, the user can monitor several parameters without using laboratory instruments, which will allow to control the entire system remotely. Moreover, the system also provides a wide range of information, which could be essential for plant researchers and provides a greater understanding of how the key parameters of hydroponic system correlate with plant growth. The proposed platform can be used both for quantitatively optimizing the setup of the indoor farming and for automating some of the most labor-intensive maintenance activities. Moreover, such a monitoring system can also potentially be used for high-level decision making, once enough data will be collected. This work presents significant opportunities for the people who live in the gulf region to produce food as per their requirements.
    Matched MeSH terms: Air Conditioning
  19. Isotope constraints of the strong influence of biomass burning to climate-forcing Black Carbon aerosols over Southeast Asia
    Liu J, Andersson A, Zhong G, Geng X, Ding P, Zhu S, et al.
    Sci Total Environ, 2020 Jul 03;744:140359.
    PMID: 32688001 DOI: 10.1016/j.scitotenv.2020.140359
    Black Carbon (BC) deteriorates air quality and contributes to climate warming, yet its regionally- and seasonally-varying emission sources are poorly constrained. Here we employ natural abundance radiocarbon (14C) measurements of BC intercepted at a northern Malaysia regional receptor site, Bachok, to quantify the relative biomass vs. fossil source contributions of atmospheric BC, in a first year-round study for SE Asia (December 2015-December 2016). The annual average 14C signature suggests as large contributions from biomass burning as from fossil fuel combustion. This is similar to findings from analogous measurements at S Asian receptors sites (~50% biomass burning), while E Asia sites are dominated by fossil emission (~20% biomass burning). The 14C-based source fingerprinting of BC in the dry spring season in SE Asia signals an even more elevated biomass burning contribution (~70% or even higher), presumably from forest, shrub and agricultural fires. This is consistent with this period showing also elevated ratio of organic carbon to BC (up from ~5 to 30) and estimates of BC emissions from satellite fire data. Hence, the present study emphasizes the importance of mitigating dry season vegetation fires in SE Asia.
    Matched MeSH terms: Air Pollution
  20. Influence of irradiance on water relations and carbon flux during rooting of Shorea leprosula leafy stem cuttings
    Aminah H, McP Dick J, Grace J
    Tree Physiol, 1997 Jul;17(7):445-52.
    PMID: 14759836
    Single-node leafy stem cuttings of Shorea leprosula Miq. were subjected to a high, intermediate or low irradiance treatment for 16 weeks in an enclosed mist propagation system. Before rooting, maximum photosynthesis of the cuttings occurred at an irradiance of 400 micro mol m(-2) s(-1). Although none of the irradiance treatments affected the number of roots produced per cutting, the numbers of cuttings that formed roots were 50 and 30% in the high irradiance (diurnal range of 0-658 micro mol m(-2) s(-1)) and low irradiance (diurnal range of 0-98 micro mol m(-2) s(-1)) treatments, respectively, compared with 62% in the intermediate irradiance treatment (diurnal range of 0-360 micro mol m(-2) s(-1)). Low rooting frequency of cuttings in the high irradiance treatment was associated with water deficits (maximum leaf-to-air vapor pressure deficit (VPD) = 3.6 kPa), whereas cuttings in the low irradiance treatment had a low rooting frequency because they were below the light compensation point most of the time. In the intermediate irradiance treatment, cuttings withstood a daily maximum VPD of 1-2 kPa and recovered overnight from the previous day's deficit, as indicated by higher relative water content (RWC) and stomatal conductance (g(s)) in the morning than in the previous afternoon and evening. Higher RWC and g(s) of cuttings in all treatments on Days 14 and 21 compared with Day 8 probably indicated recovery from water deficit following severance and insertion of the cuttings in rooting medium. There were negative relationships between stem volume of cuttings and both number of cuttings that rooted and number of roots per cutting.
    Matched MeSH terms: Air Pressure
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