Air pollution’s invisible hand on public health
By Dr. Roland Leung – respiratory medicine specialist; Co-chair of the Immunology Subcommittee in Hong Kong Institute of Allergy
Another month, another new shocking photo of China city’s smog does the rounds in the media. However these pictures do not show what the sensitive (or allergic) group has always ‘felt’, that air pollution can really impact your health.
A number of time series studies in Hong Kong all showed clear association between increase in the levels of major pollutants, including PM10 and NO2, and rise in respiratory symptoms, accident and emergency room attendance, and hospitalization for asthma and Chronic Obstructive Pulmonary Disease (COPD). The presenting symptoms ranged from runny nose, sneezing fits, nasal congestion on the mild end of the spectrum, to persistent cough that disturbs sleep, sputum production, shortness of breath, and wheeze on the severe end.
Between December and February when air pollution tends to be at its worst in Hong Kong, more patients, particularly young children and the elderly, requires hospitalization. In my private practice as a Respiratory Physician in Hong Kong in the past 20 years, I also regularly see 20-30% increase in patient visits with allergic rhinitis, bronchitis, asthma, and COPD, the few days following smoggy weather with high Air Quality Health Impact (AQHI).
There is however good news. It is clear that measures taken by the environmental protection authorities in both China and Hong Kong to curb air pollution are working. Strategies and policies directed at major emission sources in Hong Kong (motor vehicles, marine vessels, and power plants) have succeeded in a marked decrease in ambient and roadside air pollution between 1999 and 2015, according to data from the Environmental Protection Department (EPD). A welcome drop in all major pollutants, except ozone, in the Pearl River Delta (PRD) region has also been noted.
What is not clear is whether this improving trend in Hong Kong’s air quality have successfully translated into better health outcomes in the region. As a respiratory physician, I am interested in pushing for greater disclosure of public health information, such as patient data for respiratory and cardiovascular disease, detailed air pollution measurements of the patients’ living environments and so on.
The EPD is undergoing a comprehensive review to update the Air Quality Objective (AQO) by 2020. This review is an opportunity to gather together such data to benchmark and determine the effectiveness of the current various policies. I call on EPD to use the review to bring together the best expertise across Hong Kong in co-designing more novel, effective, and practical strategies, and delivering a sustained improvement in the health not just for patients but everyone – you, me and the future generations of Hong Kong.