Displaying publications 421 - 440 of 478 in total

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  1. Teoh PH, Shu-Chien AC, Chan WK
    Dev. Dyn., 2010 Mar;239(3):865-74.
    PMID: 20108353 DOI: 10.1002/dvdy.22221
    pbx1, a TALE (three-amino acid loop extension) homeodomain transcription factor, is involved in a diverse range of developmental processes. We examined the expression of pbx1 during zebrafish development by in situ hybridization. pbx1 transcripts could be detected in the central nervous system and pharyngeal arches from 24 hpf onwards. In the swim bladder anlage, pbx1 was detected as early as 28 hpf, making it the earliest known marker for this organ. Morpholino-mediated gene knockdown of pbx1 revealed that the swim bladder failed to inflate, with eventual lethality occurring by 8 dpf. The knockdown of pbx1 did not perturb the expression of prdc and foxA3, with both early swim bladder markers appearing normally at 36 and 48 hpf, respectively. However, the expression of anxa5 was completely abolished by pbx1 knockdown at 60 hpf suggesting that pbx1 may be required during the late stage of swim bladder development.
    Matched MeSH terms: Air Sacs/embryology*
  2. Shukrimi A, Aminudin CA, Azril MA, Hadi MR
    Med J Malaysia, 2006 Feb;61 Suppl A:88-90.
    PMID: 17042238
    We report a case of a previously healthy 53-year-old man who developed an intra-operative catastrophic event occurring in association with the use of hydrogen peroxide for wound irrigation following surgical debridement of a chronic osteomyelitis lesion of the humerus. It is our intention to highlight this potentially fatal consequence of hydrogen peroxide irrigation as part of bone debridement procedure. This case will serve as a reminder to orthopaedic surgeons who frequently use hydrogen peroxide in their surgical practice.
    Matched MeSH terms: Embolism, Air/chemically induced*
  3. Ee-Ling O, Mustaffa NI, Amil N, Khan MF, Latif MT
    Bull Environ Contam Toxicol, 2015 Apr;94(4):537-42.
    PMID: 25652682 DOI: 10.1007/s00128-015-1477-9
    This study determined the source contribution of PM2.5 (particulate matter <2.5 μm) in air at three locations on the Malaysian Peninsula. PM2.5 samples were collected using a high volume sampler equipped with quartz filters. Ion chromatography was used to determine the ionic composition of the samples and inductively coupled plasma mass spectrometry was used to determine the concentrations of heavy metals. Principal component analysis with multilinear regressions were used to identify the possible sources of PM2.5. The range of PM2.5 was between 10 ± 3 and 30 ± 7 µg m(-3). Sulfate (SO4 (2-)) was the major ionic compound detected and zinc was found to dominate the heavy metals. Source apportionment analysis revealed that motor vehicle and soil dust dominated the composition of PM2.5 in the urban area. Domestic waste combustion dominated in the suburban area, while biomass burning dominated in the rural area.
    Matched MeSH terms: Air Pollutants/analysis*
  4. Idris IB, Ghazi HF, Zhie KH, Khairuman KA, Yahya SK, Abd Zaim FA, et al.
    Ann Glob Health, 2016 6 22;82(1):202-8.
    PMID: 27325078 DOI: 10.1016/j.aogh.2016.01.021
    The prevalence of asthma is increasing, especially among children in Malaysia, with environmental factors as one of the main preventable contributors. The aim of this study was to determine the association between environmental air pollutants and the occurrence of asthma among children seen in pediatric clinics in Universiti Kebangsaan Malaysia Medical Center (UKMMC), Kuala Lumpur. An unmatched case control study among children who attended the pediatric clinic was carried out from May to August 2015. A total of 223 children who were diagnosed with asthma (105 cases) and who did not have asthma (118 controls) were included in this study. Their parents or caregivers were interviewed using questionnaires modified from the International Study of Asthma and Allergies in Childhood. Data obtained were analyzed using SPSS software version 20. There was a higher risk of asthma in those who had carpet at home (OR = 2.15 CI [1.25-3.68]), those who lived within 200 m of heavy traffic (OR = 1.72 CI [1.01-2.93]), and those who were exposed to lorry fumes (OR = 2.61. CI [1.38-4.93]). Environmental air pollutants increased the risk of asthma among children in Malaysia. Exposure to congested roads, lorry fumes, and indoor carpet were associated with asthma among children in this study. Parents or caretakers of children with asthma should be given adequate education on the prevention of asthmatic attack among these children.
    Study site: Paediatric clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
    Matched MeSH terms: Air Pollutants/adverse effects*
  5. Hamzah NA, Mohd Tamrin SB, Ismail NH
    Int J Occup Environ Health, 2016 07;22(3):224-232.
    PMID: 27392157 DOI: 10.1080/10773525.2016.1207040
    BACKGROUND: Metallic dust is a heterogeneous substance with respiratory sensitizing properties. Its long term exposure adversely affected lung function, thus may cause acute or chronic respiratory diseases.

    METHODS: A cross-sectional study was conducted in a steel factory in Terengganu, Malaysia to assess the metal dust exposure and its relationship to lung function values among 184 workers. Metal dust concentrations values (Co, Cr, and Ni) for each worker were collected using air personal sampling. Lung function values (FEV1, FVC, and %FEV1/FVC) were determined using spirometer.

    RESULTS: Exposure to cobalt and chromium were 1-3 times higher than permissible exposure limit (PEL) while nickel was not exceeding the PEL. Cumulative of chromium was the predictor to all lung function values (FEV1, FVC, and %FEV1/FVC). Frequency of using mask was positively associated with FVC (Adj b = 0.263, P = 0.011) while past respiratory illnesses were negatively associated with %FEV1/FVC (Adj b = -1.452, P = 0.026). Only few workers (36.4%) were found to wear their masks all times during the working hours.

    CONCLUSIONS: There was an exposure-response relationship of cumulative metal dust exposure with the deterioration of lung function values. Improvement of control measures as well as proper and efficient use or personal protection equipment while at work could help to protect the respiratory health of workers.

    Matched MeSH terms: Air Pollutants, Occupational/adverse effects*; Air Pollutants, Occupational/analysis
  6. Nazariah SS, Juliana J, Abdah MA
    Glob J Health Sci, 2013 Jul;5(4):93-105.
    PMID: 23777726 DOI: 10.5539/gjhs.v5n4p93
    In the last few years, air within homes have been indicates by various and emerging body as more serious polluted than those outdoor. Prevalence of respiratory inflammation among school children aged 8 and 10 years old attending national primary schools in urban and rural area were conducted in Klang Valley. Two population studies drawn from the questionnaires were used to investigate the association between indoor particulate matter (PM2.5 & PM10) in a home environment and respiratory implication through the understanding of biological responses. Approximately 430 healthy school children of Standard 2 and Standard 5 were selected. Indication of respiratory symptoms using adaptation questionnaire from American Thoracic Society (1978). Sputum sample collection taken for biological analysis. IL-6 then was analyse by using ELISA techniques. Indoor PM2.5 and PM10 were measured using Dust Trak Aerosol Monitor. The mean concentration of PM2.5 (45.38 µg/m3) and PM10 (80.07 µg/m3) in urban home environment is significantly higher compared to those in rural residential area (p=0.001). Similar trend also shows by the prevalence of respiratory symptom. Association were found with PM2.5 and PM10 with the level of IL-6 among school children. A greater exposure to PM2.5 and PM10 are associated with higher expression of IL-6 level suggesting that the concentration of indoor particulate in urban density area significantly influence the health of children.
    Matched MeSH terms: Air Pollution, Indoor/adverse effects*; Air Pollution, Indoor/statistics & numerical data
  7. Pedersen M, Stafoggia M, Weinmayr G, Andersen ZJ, Galassi C, Sommar J, et al.
    Eur Urol Focus, 2018 01;4(1):113-120.
    PMID: 28753823 DOI: 10.1016/j.euf.2016.11.008
    BACKGROUND: Ambient air pollution contains low concentrations of carcinogens implicated in the etiology of urinary bladder cancer (BC). Little is known about whether exposure to air pollution influences BC in the general population.

    OBJECTIVE: To evaluate the association between long-term exposure to ambient air pollution and BC incidence.

    DESIGN, SETTING, AND PARTICIPANTS: We obtained data from 15 population-based cohorts enrolled between 1985 and 2005 in eight European countries (N=303431; mean follow-up 14.1 yr). We estimated exposure to nitrogen oxides (NO2 and NOx), particulate matter (PM) with diameter <10μm (PM10), <2.5μm (PM2.5), between 2.5 and 10μm (PM2.5-10), PM2.5absorbance (soot), elemental constituents of PM, organic carbon, and traffic density at baseline home addresses using standardized land-use regression models from the European Study of Cohorts for Air Pollution Effects project.

    OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We used Cox proportional-hazards models with adjustment for potential confounders for cohort-specific analyses and meta-analyses to estimate summary hazard ratios (HRs) for BC incidence.

    RESULTS AND LIMITATIONS: During follow-up, 943 incident BC cases were diagnosed. In the meta-analysis, none of the exposures were associated with BC risk. The summary HRs associated with a 10-μg/m3 increase in NO2 and 5-μg/m3 increase in PM2.5 were 0.98 (95% confidence interval [CI] 0.89-1.08) and 0.86 (95% CI 0.63-1.18), respectively. Limitations include the lack of information about lifetime exposure.

    CONCLUSIONS: There was no evidence of an association between exposure to outdoor air pollution levels at place of residence and risk of BC.

    PATIENT SUMMARY: We assessed the link between outdoor air pollution at place of residence and bladder cancer using the largest study population to date and extensive assessment of exposure and comprehensive data on personal risk factors such as smoking. We found no association between the levels of outdoor air pollution at place of residence and bladder cancer risk.

    Matched MeSH terms: Air Pollution/adverse effects*
  8. Michaudel C, Mackowiak C, Maillet I, Fauconnier L, Akdis CA, Sokolowska M, et al.
    J Allergy Clin Immunol, 2018 09;142(3):942-958.
    PMID: 29331644 DOI: 10.1016/j.jaci.2017.11.044
    BACKGROUND: IL-33 plays a critical role in regulation of tissue homeostasis, injury, and repair. Whether IL-33 regulates neutrophil recruitment and functions independently of airways hyperresponsiveness (AHR) in the setting of ozone-induced lung injury and inflammation is unclear.

    OBJECTIVE: We sought to examine the role of the IL-33/ST2 axis in lung inflammation on acute ozone exposure in mice.

    METHODS: ST2- and Il33-deficient, IL-33 citrine reporter, and C57BL/6 (wild-type) mice underwent a single ozone exposure (1 ppm for 1 hour) in all studies. Cell recruitment in lung tissue and the bronchoalveolar space, inflammatory parameters, epithelial barrier damage, and airway hyperresponsiveness (AHR) were determined.

    RESULTS: We report that a single ozone exposure causes rapid disruption of the epithelial barrier within 1 hour, followed by a second phase of respiratory barrier injury with increased neutrophil recruitment, reactive oxygen species production, AHR, and IL-33 expression in epithelial and myeloid cells in wild-type mice. In the absence of IL-33 or IL-33 receptor/ST2, epithelial cell injury with protein leak and myeloid cell recruitment and inflammation are further increased, whereas the tight junction proteins E-cadherin and zonula occludens 1 and reactive oxygen species expression in neutrophils and AHR are diminished. ST2 neutralization recapitulated the enhanced ozone-induced neutrophilic inflammation. However, myeloid cell depletion using GR-1 antibody reduced ozone-induced lung inflammation, epithelial cell injury, and protein leak, whereas administration of recombinant mouse IL-33 reduced neutrophil recruitment in Il33-deficient mice.

    CONCLUSION: Data demonstrate that ozone causes an immediate barrier injury that precedes myeloid cell-mediated inflammatory injury under the control of the IL-33/ST2 axis. Thus IL-33/ST2 signaling is critical for maintenance of intact epithelial barrier and inflammation.

    Matched MeSH terms: Air Pollutants/toxicity*
  9. Coleman MS, Burke HM, Welstead BL, Mitchell T, Taylor EM, Shapovalov D, et al.
    Hum Vaccin Immunother, 2017 05 04;13(5):1084-1090.
    PMID: 28068211 DOI: 10.1080/21645515.2016.1271518
    Background On August 24, 2011, 31 US-bound refugees from Kuala Lumpur, Malaysia (KL) arrived in Los Angeles. One of them was diagnosed with measles post-arrival. He exposed others during a flight, and persons in the community while disembarking and seeking medical care. As a result, 9 cases of measles were identified. Methods We estimated costs of response to this outbreak and conducted a comparative cost analysis examining what might have happened had all US-bound refugees been vaccinated before leaving Malaysia. Results State-by-state costs differed and variously included vaccination, hospitalization, medical visits, and contact tracing with costs ranging from $621 to $35,115. The total of domestic and IOM Malaysia reported costs for US-bound refugees were $137,505 [range: $134,531 - $142,777 from a sensitivity analysis]. Had all US-bound refugees been vaccinated while in Malaysia, it would have cost approximately $19,646 and could have prevented 8 measles cases. Conclusion A vaccination program for US-bound refugees, supporting a complete vaccination for US-bound refugees, could improve refugees' health, reduce importations of vaccine-preventable diseases in the United States, and avert measles response activities and costs.
    Matched MeSH terms: Air Travel*
  10. Abdul Wahab S, Hassan A, Latif MT, Vadiveel Y, Jeyabalan T, Soo CI, et al.
    Asian Pac J Cancer Prev, 2019 07 01;20(7):1959-1965.
    PMID: 31350951 DOI: 10.31557/APJCP.2019.20.7.1959
    Objective: Epidemiological studies have reported the close relationship between risk for lung cancers and air pollution
    in particular, for non-smoking related lung cancers. However, most studies used residential address as proxies which may
    not estimate accurately an individual’s air pollution exposure. Therefore, the aim of this study was to identify risk factors
    such as occupation and mode of transportation associated with lung cancer diagnosis and death. Methods: Subjects
    with lung cancer (n=514) were evaluated both by chart reviews for clinical data and interviews to determine residential
    address for ten years, main occupation and main mode of transportation. Annual particulate matter with diameter size
    less than 2.5 micrometre (PM2.5) concentration were calculated based on particulate matter with diameter size less than
    10 micrometre (PM10) data recorded by Malaysian Department of Environment. Logistic regression analysis, cluster
    analysis and the Cox regression analysis were performed to the studied variables. Results: This study concurred with
    previous studies that lung adenocarcinoma were diagnosed in predominantly younger, female non-smokers compared
    to the other types of lung cancers. Lung adenocarcinoma subjects had annual PM2.5 that was almost twice higher than
    squamous cell carcinoma, small cell carcinoma and other histological subtypes (p=0.024). Independent of smoking,
    the κ -means cluster analysis revealed two clusters in which the high risk cluster involves occupation risk with air
    pollution of more than four hours per day, main transportation involving motorcycle and trucks and mean annual PM2.5
    concentration of more than 30 based on residential address for more than ten years. The increased risk for the high-risk
    cluster was more than five times for the diagnosis of lung adenocarcinoma (OR=5.69, 95% CI=3.14-7.21, p<0.001).
    The hazard ratio for the high-risk cluster was 3.89 (95% CI=2.12-4.56, p=0.02) for lung adenocarcinoma mortality at
    1 year. Conclusion: High-risk cluster including PM2.5, occupation risk and mode of transportation as surrogates for
    air-pollution exposure was identified and highly associated with lung adenocarcinoma diagnosis and 1-year mortality.
    Matched MeSH terms: Air Pollution/adverse effects*
  11. Opstelten JL, Beelen RMJ, Leenders M, Hoek G, Brunekreef B, van Schaik FDM, et al.
    Dig Dis Sci, 2016 Oct;61(10):2963-2971.
    PMID: 27461060 DOI: 10.1007/s10620-016-4249-4
    BACKGROUND: Industrialization has been linked to the etiology of inflammatory bowel disease (IBD).

    AIM: We investigated the association between air pollution exposure and IBD.

    METHODS: The European Prospective Investigation into Cancer and Nutrition cohort was used to identify cases with Crohn's disease (CD) (n = 38) and ulcerative colitis (UC) (n = 104) and controls (n = 568) from Denmark, France, the Netherlands, and the UK, matched for center, gender, age, and date of recruitment. Air pollution data were obtained from the European Study of Cohorts for Air Pollution Effects. Residential exposure was assessed with land-use regression models for particulate matter with diameters of <10 μm (PM10), <2.5 μm (PM2.5), and between 2.5 and 10 μm (PMcoarse), soot (PM2.5 absorbance), nitrogen oxides, and two traffic indicators. Conditional logistic regression analyses were performed to calculate odds ratios (ORs) with 95 % confidence intervals (CIs).

    RESULTS: Although air pollution was not significantly associated with CD or UC separately, the associations were mostly similar. Individuals with IBD were less likely to have higher exposure levels of PM2.5 and PM10, with ORs of 0.24 (95 % CI 0.07-0.81) per 5 μg/m(3) and 0.25 (95 % CI 0.08-0.78) per 10 μg/m(3), respectively. There was an inverse but nonsignificant association for PMcoarse. A higher nearby traffic load was positively associated with IBD [OR 1.60 (95 % CI 1.04-2.46) per 4,000,000 motor vehicles × m per day]. Other air pollutants were positively but not significantly associated with IBD.

    CONCLUSION: Exposure to air pollution was not found to be consistently associated with IBD.

    Matched MeSH terms: Air Pollution/statistics & numerical data*
  12. Azizi BH, Henry RL
    Pediatr Pulmonol, 1990;9(1):24-9.
    PMID: 2388776
    In a cross-sectional study of 7-12 year-old primary school children in Kuala Lumpur city, lung function was assessed by spirometric and peak expiratory flow measurements. Spirometric and peak expiratory flow measurements were successfully performed in 1,214 and 1,414 children, respectively. As expected, the main predictors of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), and peak expiratory flow rate (PEFR) were standing height, weight, age, and sex. In addition, lung function values of Chinese and Malays were generally higher than those of Indians. In multiple regression models which included host and environmental factors, asthma was associated with significant decreases in FEV1, FEF25-75, and PEFR. However, family history of chest illness, history of allergies, low paternal education, and hospitalization during the neonatal period were not independent predictors of lung function. Children sharing rooms with adult smokers had significantly lower levels of FEF25-75. Exposures to wood or kerosene stoves were, but to mosquito repellents were not, associated with decreased lung function.
    Matched MeSH terms: Air Pollutants/adverse effects*
  13. Norbäck D, Hashim JH, Hashim Z, Ali F
    Sci Total Environ, 2017 Aug 15;592:153-160.
    PMID: 28319702 DOI: 10.1016/j.scitotenv.2017.02.215
    This paper studied associations between volatile organic compounds (VOC), formaldehyde, nitrogen dioxide (NO2) and carbon dioxide (CO2) in schools in Malaysia and rhinitis, ocular, nasal and dermal symptoms, headache and fatigue among students. Pupils from eight randomly selected junior high schools in Johor Bahru, Malaysia (N=462), participated (96%). VOC, formaldehyde and NO2 were measured by diffusion sampling (one week) and VOC also by pumped air sampling during class. Associations were calculated by multi-level logistic regression adjusting for personal factors, the home environment and microbial compounds in the school dust. The prevalence of weekly rhinitis, ocular, throat and dermal symptoms were 18.8%, 11.6%, 15.6%, and 11.1%, respectively. Totally 20.6% had weekly headache and 22.1% fatigue. Indoor CO2 were low (range 380-690 ppm). Indoor median NO2 and formaldehyde concentrations over one week were 23μg/m3 and 2.0μg/m3, respectively. Median indoor concentration of toluene, ethylbenzene, xylene, and limonene over one week were 12.3, 1.6, 78.4 and 3.4μg/m3, respectively. For benzaldehyde, the mean indoor concentration was 2.0μg/m3 (median<1μg/m3). Median indoor levels during class of benzene and cyclohexane were 4.6 and 3.7μg/m3, respectively. NO2 was associated with ocular symptoms (p<0.001) and fatigue (p=0.01). Formaldehyde was associated with ocular (p=0.004), throat symptoms (p=0.006) and fatigue (p=0.001). Xylene was associated with fatigue (p<0.001) and benzaldehyde was associated with headache (p=0.03). In conclusion, xylene, benzaldehyde, formaldehyde and NO2 in schools can be risk factors for ocular and throat symptoms and fatigue among students in Malaysia. The indoor and outdoor levels of benzene were often higher than the EU standard of 5μg/m3.
    Matched MeSH terms: Air Pollution, Indoor/adverse effects*
  14. Tan PS, Genc F, Delgado E, Kellum JA, Pinsky MR
    Intensive Care Med, 2002 Aug;28(8):1064-72.
    PMID: 12185426
    We tested the hypothesis that NO contamination of hospital compressed air also improves PaO(2) in patients with acute lung injury (ALI) and following lung transplant (LTx).
    Matched MeSH terms: Air/analysis*
  15. Abdul Rahman HI, Shah SA, Alias H, Ibrahim HM
    Asian Pac J Cancer Prev, 2008 Oct-Dec;9(4):649-52.
    PMID: 19256754
    BACKGROUND: In Malaysia, acute leukemia is the most common cancer among children below the age of 15. A case-control study was here conducted for cases from the Klang Valley, Malaysia, who received treatment at the National University of Malaysia Hospital (HUKM) and Kuala Lumpur General Hospital (GHKL). The main objective was to determine any association with environmental factors.

    METHODS: Case subjects were children aged below 15 years and diagnosed with acute leukemia in HUKM and GHKL between January 1, 2001 and May 30, 2007. Control subjects were children aged below 15 years who were diagnosed with any non-cancerous acute illnesses in these hospitals. A total of 128 case subjects and 128 control subjects were enrolled in this study. The information was collected using a structured questionnaire and a global positioning system (GPS) device. All factors were analyzed using unmatched logistic regression.

    RESULTS: The analysis showed that the occurrence of acute leukemia among children was strongly determined by the following factors: family income (odds ratio (OR) 0.19, 95% confidence interval (CI): 0.09-0.42), father with higher social contact (OR 7.61, 95% CI: 3.78-15.4), number of elder siblings (OR 0.36, 95% CI: 0.18-0.77), father who smokes (OR 2.78, 95% CI: 1.49-5.16), and the distance of the house from a power line (OR 2.30, 95% CI: 1.18-4.49).

    CONCLUSIONS: Some socioeconomic, demographic, and environmental factors are strong predictors of the occurrence of acute leukemia among children in Klang Valley, Malaysia. In terms of environmental factors, it is recommended that future housing areas should be developed at least 200 m away from power lines.
    Matched MeSH terms: Air Pollution, Indoor/statistics & numerical data*
  16. Chan LL, Mak JW, Low YT, Koh TT, Ithoi I, Mohamed SM
    Acta Trop, 2011 Jan;117(1):23-30.
    PMID: 20858455 DOI: 10.1016/j.actatropica.2010.09.004
    During a study on the quality of the indoor environment, Acanthamoeba spp. were detected in 20 out of 87 dust samples collected from air-conditioners installed in a four-story campus building located in Kuala Lumpur, Malaysia. Twenty-one cloned Acanthamoeba isolates designated as IMU1 to IMU21 were established from the positive primary cultures. Five species were identified from the 16 isolates according to the morphological criteria of Pussard and Pons; i.e. A. castellanii, A. culbertsoni, A. griffini, A. hatchetti and A. polyphaga. Species identities for the remaining five isolates (IMU4, IMU5, IMU15, IMU20 and IMU21), however, could not be determined morphologically. At genotypic characterization, these isolates were placed into T3 (IMU14); T5 (IMU16 and IMU17) and T4 (all the remaining isolates). To predict the potential pathogenicity of these Acanthamoeba isolates, thermo- and osmotolerance tests were employed; many isolates were predicted as potential human pathogens based on the outcome of these tests. This is the first time potentially pathogenic Acanthamoeba have been isolated from air-conditioners in Malaysia.
    Matched MeSH terms: Air Conditioning*
  17. Hewitt CN, MacKenzie AR, Di Carlo P, Di Marco CF, Dorsey JR, Evans M, et al.
    Proc Natl Acad Sci U S A, 2009 Nov 3;106(44):18447-51.
    PMID: 19841269 DOI: 10.1073/pnas.0907541106
    More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an "environmentally friendly" fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O(3)), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O(3) concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O(3) concentrations will reach 100 parts per billion (10(9)) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.
    Matched MeSH terms: Air Pollution/analysis*
  18. Pyle JA, Warwick NJ, Harris NR, Abas MR, Archibald AT, Ashfold MJ, et al.
    Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3210-24.
    PMID: 22006963 DOI: 10.1098/rstb.2011.0060
    We present results from the OP3 campaign in Sabah during 2008 that allow us to study the impact of local emission changes over Borneo on atmospheric composition at the regional and wider scale. OP3 constituent data provide an important constraint on model performance. Treatment of boundary layer processes is highlighted as an important area of model uncertainty. Model studies of land-use change confirm earlier work, indicating that further changes to intensive oil palm agriculture in South East Asia, and the tropics in general, could have important impacts on air quality, with the biggest factor being the concomitant changes in NO(x) emissions. With the model scenarios used here, local increases in ozone of around 50 per cent could occur. We also report measurements of short-lived brominated compounds around Sabah suggesting that oceanic (and, especially, coastal) emission sources dominate locally. The concentration of bromine in short-lived halocarbons measured at the surface during OP3 amounted to about 7 ppt, setting an upper limit on the amount of these species that can reach the lower stratosphere.
    Matched MeSH terms: Air Pollution/analysis*
  19. MacKenzie AR, Langford B, Pugh TA, Robinson N, Misztal PK, Heard DE, et al.
    Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3177-95.
    PMID: 22006961 DOI: 10.1098/rstb.2011.0053
    We report measurements of atmospheric composition over a tropical rainforest and over a nearby oil palm plantation in Sabah, Borneo. The primary vegetation in each of the two landscapes emits very different amounts and kinds of volatile organic compounds (VOCs), resulting in distinctive VOC fingerprints in the atmospheric boundary layer for both landscapes. VOCs over the Borneo rainforest are dominated by isoprene and its oxidation products, with a significant additional contribution from monoterpenes. Rather than consuming the main atmospheric oxidant, OH, these high concentrations of VOCs appear to maintain OH, as has been observed previously over Amazonia. The boundary-layer characteristics and mixing ratios of VOCs observed over the Borneo rainforest are different to those measured previously over Amazonia. Compared with the Bornean rainforest, air over the oil palm plantation contains much more isoprene, monoterpenes are relatively less important, and the flower scent, estragole, is prominent. Concentrations of nitrogen oxides are greater above the agro-industrial oil palm landscape than over the rainforest, and this leads to changes in some secondary pollutant mixing ratios (but not, currently, differences in ozone). Secondary organic aerosol over both landscapes shows a significant contribution from isoprene. Primary biological aerosol dominates the super-micrometre aerosol over the rainforest and is likely to be sensitive to land-use change, since the fungal source of the bioaerosol is closely linked to above-ground biodiversity.
    Matched MeSH terms: Air Pollutants/chemistry
  20. Cai GH, Hashim JH, Hashim Z, Ali F, Bloom E, Larsson L, et al.
    Pediatr Allergy Immunol, 2011 May;22(3):290-7.
    PMID: 21457336 DOI: 10.1111/j.1399-3038.2010.01127.x
    While there is a large variation of prevalence of asthma symptoms worldwide, what we do know is that it is on the rise in developing countries. However, there are few studies on allergens, moulds and mycotoxin exposure in schools in tropical countries. The aims were to measure selected fungal DNA, furry pet allergens and mycotoxins in dust samples from schools in Malaysia and to study associations with pupils' respiratory health effects. Eight secondary schools and 32 classrooms in Johor Bahru, Malaysia were randomly selected. A questionnaire with standardized questions was used for health assessment in 15 randomly selected pupils from each class. The school buildings were inspected and both indoor and outdoor climate were measured. Dust samples were collected by cotton swabs and Petri dishes for fungal DNA, mycotoxins and allergens analysis. The participation rate was 96% (462/480 invited pupils), with a mean age of 14 yr (range 14-16). The pupils mostly reported daytime breathlessness (41%), parental asthma or allergy (22%), pollen or pet allergy (21%) and doctor-diagnosed asthma (13%) but rarely reported night-time breathlessness (7%), asthma in the last 12 months (3%), medication for asthma (4%) or smoking (5%). The inspection showed that no school had any mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures. The mean building age was 16 yr (range 3-40) and the mean indoor and outdoor CO(2) levels were 492 ppm and 408 ppm, respectively. The mean values of indoor and outdoor temperature and relative humidity were the same, 29°C and 70% respectively. In cotton swab dust samples, the Geometric Mean (GM) value for total fungal DNA and Aspergillus/Penicillium (Asp/Pen) DNA in swab samples (Cell Equivalents (CE)/m(2)) was 5.7*10(8) and 0.5*10(8), respectively. The arithmetic mean (CE/m(2)) for Aspergillus versicolor DNA was 8780, Stachybotrys chartarum DNA was 26 and Streptomyces DNA was 893. The arithmetic means (pg/m(2)) for the mycotoxins sterigmatocystin and verrucarol were 2547 and 17, respectively. In Petri dish dust samples, the GM value for total fungal DNA and Asp/Pen DNA (CE/m(2) per day) was 9.2*10(6) and 1.6*10(6), respectively. The arithmetic mean (CE/m(2) per day) for A. versicolor DNA was 1478, S. chartarum DNA was 105 and Streptomyces DNA was 1271, respectively. The GM value for cat (Fel d1) allergen was 5.9 ng/m(2) per day. There were positive associations between A. versicolor DNA, wheeze and daytime breathlessness and between Streptomyces DNA and doctor-diagnosed asthma. However, the associations were inverse between S. chartarum DNA and daytime breathlessness and between verrucarol and daytime breathlessness. In conclusion, fungal DNA and cat allergen contamination were common in schools from Malaysia and there was a high prevalence of respiratory symptoms among pupils. Moreover, there were associations between levels of some fungal DNA and reported respiratory health in the pupils.
    Matched MeSH terms: Air Pollution, Indoor/analysis
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