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Hong Kong is a beautiful city. AIR POLLUTION IN HONG KONG and the PEARL RIVER DELTA. However, sometimes less so…. AJ Hedley 1 , SM McGhee 1 , W Barron 2 , PYK Chau 1 , J Chau 1 , TQ Thach 1 , TW Wong 3 , C Loh 4 , CM Wong 1 1 University of Hong Kong
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Hong Kong is a beautiful city AIR POLLUTION IN HONG KONG and the PEARL RIVER DELTA However, sometimes less so… AJ Hedley1, SM McGhee1, W Barron2, PYK Chau1, J Chau1, TQ Thach1, TW Wong3, C Loh4, CM Wong1 1 University of Hong Kong 2University of Science and Technology 3 Chinese University of Hong Kong 4 Civic Exchange Sunday 1 August 2004 Tuesday 4 January 2005 Photo: Edward Stokes; Hong Kong Conservation Photography Foundation Photo: Edward Stokes; Hong Kong Conservation Photography Foundation
Department of Community Medicine, School of Public Health, University of Hong Kong
BAD AIR, BAD PRESS Department of Community Medicine, School of Public Health, University of Hong Kong
100 80 60 40 20 0 HONG KONG IS WORSE THAN MOST CITIES Pollution (RSP) Shanghai, Guangzhou 2004 (99) (microgram per cubic meter) Hong Kong roadside 2004 (80) Hong Kong 2004 (62) Hong Kong AQO Los Angeles 2003 (44) London 2005 (30) New York 2003 (22) WHO AQG Paris 2003 (21) Vancouver 2004 (13) Department of Community Medicine, School of Public Health, University of Hong Kong
Monthly concentration of PM10 in year 2001-05 Concentration (mg/m3) Hong Kong PM10 AQO (annual) = 55 Proposed WHO PM10 (annual) = 20 Roadside General Time Source: Environmental Protection Department/ Department of Community Medicine HKU Department of Community Medicine, School of Public Health, University of Hong Kong
The Hong Kong air quality intervention 1990 BeforeAfter Kwai Tsing On July 1st 1990 the Environmental Protection Department restricted the sulphur content of fuel to 0.5% by weight Department of Community Medicine, School of Public Health, University of Hong Kong
80 Fuel restriction on sulphur PM10 60 NO2 50% reduction in SO2 after the intervention SO2 Micrograms per cubic metre 40 O3 20 No change in other pollutants 0 1988 1989 1990 1991 1992 1993 1994 1995 Year AIR POLLUTANT CONCENTRATIONS 1988 - 95 IN HONG KONG HALF YEARLY MEAN LEVELS Department of Community Medicine, School of Public Health, University of Hong Kong
Nickel (Ni) Vanadium (V) Effect of conversion to low sulfur fuel (0.5%) on transition metals mbefore=24.73; mafter =3.95; p =0.000 mbefore=9.48; mafter =2.87; p =0.000 Department of Community Medicine, School of Public Health, University of Hong Kong
Reductions in cardiopulmonary deaths after sulfur restriction 1990 0 -1 -2 -1.6% -1.8% -2.4% % Reduction in annual trend -3 -2.8% -4 -4.2% -5 -4.8% -6 15-64 65+ 15-64 65+ 15-64 65+ All causes Cardiovascular Respiratory Department of Community Medicine, School of Public Health, University of Hong Kong
Monthly Trends of SO2, Ni, V in Year 2001-04 SO2 V Ni p=0.001 Concentration (SO2: mg/m3; V/Ni: ng/m3) p=0.129 p=0.048 Month Data source: HKEPD; Plotting: Chau/Hedley 2006 Department of Community Medicine, School of Public Health, University of Hong Kong
Hong Kong: Annual decline in visibility Hazy days Number per year Year Source: Hong Kong Observatory Department of Community Medicine, School of Public Health, University of Hong Kong
An analysis directed to GovernmentLegislators, media and public Understanding the connection between visibility, air pollution and health costs in pursuit of accountability, environmental justice and health protection Department of Community Medicine, School of Public Health, University of Hong Kong
Visibility and pollutants in Hong Kong MICROGRAM PER CUBIC METER Source of data: Environmental Protection Department Department of Community Medicine, School of Public Health, University of Hong Kong
12.8 Hourly visibility on the days the photographs were taken Source of data: Hong Kong Observatory Department of Community Medicine, School of Public Health, University of Hong Kong
Four levels of air quality: General and roadside * Based on general monitoring stations except the background monitoring station at Tap Mun Chau Department of Community Medicine, School of Public Health, University of Hong Kong
Potential improvements in air quality in Hong Kong % of days at these levels in Hong Kong Pollution 2% (microgram per cubic meter) Poor 100 43% average to better 80 Hong Kong2004 (62) Average 60 44% 40 Better 8% 20 Good 2% average to good 0 Department of Community Medicine, School of Public Health, University of Hong Kong
Doctor visits, hospital admissions and deaths: Excess risks and avoidable events • From time series, excess risks of: • * family doctor visits • * hospital admissions for cardiopulmonary disease • * all causes mortality • For each pollutant (P) we estimated the impact (I), as avoidable events for each health outcome, from air quality improvement as • NI *ERP *LP = IP Avoidable events • and • IP * CI = Avoidable costs Department of Community Medicine, School of Public Health, University of Hong Kong
UNIT COSTS IN ESTIMATION OF AVOIDABLE COSTS • From gazetted public sector and surveys costs of: * in-patient and ambulatory care * travel costs * productivity loss • From surveys, willingness-to-pay to avoid: * symptoms (cough) day * hospital admission * death Department of Community Medicine, School of Public Health, University of Hong Kong
Estimation of health impact and costs: Single or multiple pollutants? • In Shanghai, Wuhan and Hong Kong the largest mortality excess risks are for NO2 and SO2, robust in 2-pollutant models • The Hong Kong sulfur restriction led to reduction in mortality of 1% per 10µg/m3 SO2 in the absence of change in RSP, NO2 and O3 • In Hong Kong the largest effect on hospital admissions for cardiopulmonary disease is associated with NO2; in London with RSP Department of Community Medicine, School of Public Health, University of Hong Kong
NO2 RSP (41%) SO2 (84%) Correlation between NO2 and RSP Partial correlation between RSP and SO2 adjusted by NO2 Correlation between pollutants (1-[0.768]2) = 0.41 NO2 (1-[0.067]2 – [0.39]2) = 0.84 SO2 Partial correlation between NO2 and SO2 adjusted by RSP Department of Community Medicine, School of Public Health, University of Hong Kong
Estimating the total contribution of pollutants to the burden of health effects and costs • Main estimate: • T = RSP + 0.41 NO2 + 0.84 SO2 + O3 • Sensitivity analysis: • “At least impact”-highest single pollutant effect • for each outcome • RSP + O3 (WHO 2003) • SO2 intervention effect (mortality) Department of Community Medicine, School of Public Health, University of Hong Kong
Avoidable events: Deaths Pollution (microgram per cubic meter) Poor Hong Kong2004 100 80 Average 60 1,300 40 Better Good 20 0 Department of Community Medicine, School of Public Health, University of Hong Kong
Avoidable events: Hospital bed days Pollution (microgram per cubic meter) Poor Hong Kong2004 100 80 Average 60 60,000 40 Better Good 20 0 Department of Community Medicine, School of Public Health, University of Hong Kong
Avoidable events: Doctor visits Pollution (microgram per cubic meter) Poor Hong Kong2004 100 80 Average 60 6,700,000 40 Better Good 20 0 Department of Community Medicine, School of Public Health, University of Hong Kong
Annual $ Value of air quality improvement Direct health costs & productivity loss avoided Intangible costs for pain & suffering Total: US$246M Total: US$2250M US$ M US$ M + Department of Community Medicine, School of Public Health, University of Hong Kong
Results of sensitivity analysis on annual avoidable mortality and costs if pollution levels reduce from Average to Good levels * Mortality NO2; Admissions NO2; Family doctor visits RSP Department of Community Medicine, School of Public Health, University of Hong Kong
THE HKSAR GOVERNMENT RESPONSE • “The costs are indirect” • “Other cities have worse levels of pollution” • “More evidence is needed on health effects” • People need to understand that “clearer skies may cost consumers more” Department of Community Medicine, School of Public Health, University of Hong Kong
Department of Community Medicine, School of Public Health, University of Hong Kong
RSP: Projected trends in Hong Kong Roadside Reach HK AQO = Year 2008 Reach Canadian guideline = Year 2015 Reach NZ guideline = Year 2016 Canada guideline (24hr) = 25 NZ guideline (annual) = 20 Non-roadside Reach HK AQO = Year 1996 Reach Canada guideline = Year 2026 Reach NZ guideline = After year 2031 Department of Community Medicine, School of Public Health, University of Hong Kong
THE NEED for EFFECTIVE MULTI-SECTORAL STRATEGIES • Local and regional sources • Near term technical solutions • Mid term technical priorities • Long term structural solutions • * Cleaner fuels * Urban design • * Euro IV & V * Manufacturing • * Flue gas sulpurization * Power sector • * Rail rather than roads * Transport Department of Community Medicine, School of Public Health, University of Hong Kong
Department of Community Medicine, School of Public Health, University of Hong Kong