Suchergebnisse

We conducted a health impact assessment of the government's proposed new air quality objectives (AQO) in Hong Kong, a high pollution environment. We based this on the World Health Organization (WHO) 2005 Air Quality Guidelines (AQG) and used a lognormal probability density function to model possible changes in annual mean pollutant levels resulting from the new AQO. All of the proposed short-term AQO were based on WHO interim targets (IT) or AQG, but allowed additional exceedances of these single limit values. Compliance with these short-term AQO may reduce (18-30%) the current annual mean concentrations but the distribution proportions exceeding the annual or annualized AQG remain high (83-100%). For SO2, the proposed 24-hr AQO of 125 µg m-3, with 3 days exceedances, cannot ensure reduction of the current annual mean but may legally permit an increase of the pollutant concentration distribution. If the proposed legal limits of AQO are fully exploited by polluters, we estimated the annual number of avoidable deaths at 1860, and avoidable health care events at 5.2 million doctor visits and 92745 hospital bed-days with a total annual community cost of US$2.6 billion. The proposed AQO may only reduce the current air pollution health impacts by 17% but could achieve 41% reduction if additional exceedances were not permitted. An epidemiologic approach should be adopted to assess external costs arising from modifications of WHOAQG and support accountability in air quality management. This analysis of the WHOAQG in a high pollution setting demonstrates problems arising from the absence of annual limits for some pollutants and the discordance between the short-term and annual AQG, suggesting that revisions based on a lognormal probability model should be considered. ; published_or_final_version

Study objective - To identify factors associated with smoking behaviour in primary school children in Hong Kong. Design - A cross sectional survey in which both children and parents completed questionnaires. The main outcome measure was the smoking status of the children; and risk factors (knowledge of and attitude to smoking and demographic and socioeconomic background) were identified as predictors of ever/never smoking. Setting and subjects - Altogether 9598 primary school children, aged 8-13 years, and attending 27 schools from two districts in Hong Kong participated. Main results - The prevalence of ever-smoking was 12% (1119)-15% (760) in boys and 7% (359) in girls. It ranged from 3% in 8 year old girls to 52% in 13 year old boys. The factors associated with ever-smoking included the following: being a boy (adjusted odds ratio 2.21; 95% confidence interval 1.89, 2.59), increasing age per year (1.48; 1.40, 1.57), living in Kwai Tsing district (1.29; 1.10, 1.50), having one or more smokers at home (2.07; 1.78, 2.39), and having a father who was not working (1.41; 1.19, 1.67). Children who were ever-smokers had both seen and approved of their friends) smoking (8.79; 5.33, 14.50), had a more positive attitude towards smoking (3.35; 2.21, 5.09), and were more successful in recognising cigarette brand names and logos (1.67; 1.42, 1.96), but they lacked confidence (1.78; 1.32, 2.39). Conclusions - The influences on child smoking are multifactorial and programmes in Hong Kong are failing to curb them. The control of these risk factors must be incorporated in the smoking prevention policy of Hong Kong and supported by future enforced legislation. ; published_or_final_version

Background. Two-thirds of complaints received by the Hong Kong Environmental Protection Department in 1988 were related to poor air quality. In July 1990 legislation was implemented to reduce fuel sulphur levels. The objective of this study was to measure the impact of the intervention on respiratory health in primary school children. Methods. In all, 3521 children, mean age 9.51 years (SD = 0.78), from two districts with good and poor air quality respectively before intervention were followed yearly from 1989 to 1991. Children and parents reported the children's respiratory symptoms using self-completed questionnaires. Factor analysis was used to derive independent scores from 12 symptoms. Four groups of related symptoms were identified and binary variables (presence of any symptom in each group) were treated as dependent variables in modelling using generalized estimating equations procedures. Results. In 1989 and 1990 an excess of respiratory symptoms was observed in the polluted compared with unpolluted district. The significant effects (odds ratio [OR], 95% confidence interval [CI], P value) associated with living in the polluted district were: cough and sore throat (OR = 1.22, 95% CI: 1.04-1.43, P < 0.01) and wheezing (OR = 1.35, 95% CI: 1.10-1.66, P < 0.01). After the intervention, in the polluted district only, sulphur dioxide levels fell by up to 80% and sulphate concentrations in respirable particulates by 38%. Between 1989 and 1990-1991 there was a greater decline in the polluted compared with the unpolluted district for reported symptoms of cough or sore throat, phlegm, and wheezing. The risks to respiratory health for children exposed to tobacco smoke in the home were higher than those for air pollution in both 1989 and 1990 and remained unchanged in 1991. Conclusions. Air quality can be improved by fuel controls but an effective intersectoral approach is required if other risks from environmental tobacco smoke are to be avoided. ; published_or_final_version

Study objective - This study examined the impact on children's respiratory health of a government air quality intervention that restricted the sulphur content of fuels to 0.5% from July 1990 onwards. Design/setting/participants - This study examined the changes, one and two years after the introduction of the intervention, in airway hyperreactivity of non-asthmatic and non-wheezing, primary 4, 5, and 6, school children aged 9-12 years living in a polluted district compared with those in a less polluted district. Bronchial hyperreactivity (BHR) (a 20% decrease in FEV, provoked by a cumulative dose of histamine less than 7.8 μmol) and bronchial reactivity slope (BR slope) (percentage change in logarithmic scale in FEV, per unit dose of histamine) were used to estimate responses to a histamine challenge. The between districts differences after the intervention were studied to assess the effectiveness of the intervention. Main results - In cohorts, comparing measurements made before the intervention and one year afterwards, both BHR and BR slope declined from 29% to 16% (p = 0.026) and from 48 to 39 (p = 0.075) respectively in the polluted district; and from 21% to 10% (p = 0.001) and 42 to 36 (p > 0.100) in the less polluted district. Comparing measurements made in 1991 (one year after intervention) with those in 1992 (two years after intervention), only the polluted district showed a significant decline from 28% to 12% (p = 0.016) and from 46 to 35 (p = 0.014), for BHR and BR slope respectively, with a greater decline in both responses (p = 0.018 and 0.073) than in the less polluted district. Conclusion - Bronchial hyperresponsiveness tests can be used to support the evaluation of an air quality intervention. The demonstrated reduction in bronchial hyperresponsiveness is an indication of the effectiveness of the intervention. ; published_or_final_version

Introduction: Smoke-free workplace legislation often exempts certain venues. Do smoking (exempted) and nonsmoking (nonexempted) catering premises' workers in Hong Kong report different perceptions of risk from and reactions to nearby smoking as well as actual exposure to secondhand smoke (SHS)? Methods: In a cross-sectional survey of 204 nonsmoking catering workers, those from 67 premises where smoking is allowed were compared with workers from 36 nonsmoking premises in Hong Kong on measures of perceptions of risk and behavioral responses to self-reported SHS exposure, plus independent exposure assessment using urinary cotinine. Results: Self-reported workplace SHS exposure prevalence was 57% (95% CI = 49%-65%) in premises prohibiting and 100% (95% CI = 92%-100%) in premises permitting smoking (p < .001). Workers in smoking-permitted premises perceived workplace air quality as poorer (odds ratio [OR] = 9.3, 95% CI = 4.2-20.9) with higher associated risks (OR = 3.7, 95% CI = 1.6-8.6) than workers in smoking-prohibited premises. Workers in smoking-prohibited premises were more bothered by (OR = 0.2, 95% CI = 0.1-0.5) and took more protective action to avoid SHS (OR = 0.2, 95% CI = 0.1-0.4) than workers in smoking-permitted premises. Nonwork exposure was negatively associated with being always bothered by nearby smoking (OR = 0.3, 95% CI = 0.1-0.9), discouraging nearby smoking (OR = 0.5, 95% CI = 0.2-1.1), and discouraging home smoking (OR = 0.4, 95% CI = 0.2-0.9). Urinary cotinine levels were inversely related to workers' avoidance behavior but positively related to their perceived exposure-related risks. Conclusions: Different workplace smoking restrictions predicted actual SHS exposure, exposure-related risk perception, and protective behaviors. Workers from smoking-permitted premises perceived greater SHS exposure-related risks but were more tolerant of these than workers in smoking-prohibited premises. This tolerance might indirectly increase both work and nonwork exposures. © The Author 2011. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. ; postprint