12 Mar 2009

Air Pollution Index

Last month, a group of medical students from our sister university took to the streets in protest and urged the government to update the Air Pollution Index (API). Do I support the act? Of course. Do I support the proposition? I am afraid not.

The protest was an excellent piece of civil education. I hope our students would join some of these activities, too. The real question is – does updating the API do any good?

Currently, the Environmental Protection Department provides the API based on the level of 6 atmospheric pollutants, including sulfur dioxide, nitrogen dioxide, suspended particulates, carbon monoxide, ozone and lead. The index and air quality objectives were set in 1987. Actually, the medical students were not the first to criticize that the index was not update. In October 2005, Task Force on Air Pollution has already stated that the current API is ‘meaningless’. First, some harmful components are not measured. Second, our cutoffs fall short of the World Health Organization Air Quality Guidelines.

I do not doubt that the experts know a lot more about the relationship between air pollution and disease. But what if we update the API? Can we shut down a few factories in Guangdong on bad days? Can we ask our drivers not to drive? Don’t be silly. You may argue – at least we can warn patients with lung diseases not to go outdoors, right?

People working in hospitals in Hong Kong may recall that we have an alert system for avian influenza. It is funny to use the word ‘recall’ for something in the present. The trouble is we are always on yellow alert. When you are always on alert, you have no choice but to ignore it. According to Prof Anthony Hedley of the Task Force, the air pollution of Hong Kong should be stated as ‘absolutely sky high’ most of the year. Can we ask the poor men to stay at home most of the year?

At the end of my hematology rotation as a medical student, I gathered my guts and asked. “Professor GC, our patients come in every few weeks for blood transfusion, but most of them do not have a diagnosis. Wouldn’t it be nice if we perform bone marrow exam and know what we are dealing with?”

“Investigations should only be done when they change the management,” the hematologist answered. “If these people suffer from myelodysplastic syndrome, I will provide supportive transfusion. If they turn out to have leukemia, I will still provide supportive transfusion.”

So forget about more investigations. The government certainly knows that the air pollution is bad. What we should push for is the means to combat pollution, not how to measure it.

1 comment: