The other day I visited my doctor for a follow-up on treatment of a bout of sinusitis. Since this was the third one in about two years, I went with a list of questions about what environmental factors might be making me more disposed to the condition. During my quick research prior to the visit, in addition to all of the normal contributing factors (allergens, pollutants, sensitivity to temperature and humidity) I also came across a number of mentions where heightened greenhouse gas levels increased inhaled allergen responsiveness in some patients. It occurred to me that this had the potential to be a new link between what I study in my professional life and what I deal with in my personal one, and I set about on some more digging.
This all started last month, while in China. Though I traveled further north than Beijing and as far south as Hong Kong, my wife Min and I spent a fair amount of time in Shanghai, China’s cosmopolitan business hub. Like Los Angeles, air quality in Shanghai has good days and bad days, though on average pollution levels exceed those of most comparable large cities in developed countries. It was not outdoor factors, however, but the hotel room that provided the first olfactory assault of the journey. The hotel receptionist was quite pleased to boast that we would be staying on the most newly renovated level of the building. We found out that this meant an up close and personal encounter with off-gassing from toxic adhesives and paint that was so oppressive we asked for a new (old) room. I am guessing some fun chit chat about that “weird foreigner” was had at my expense, but I was just happy to breathe.
Room situation resolved, I set about planning my one unadulterated (no meeting) day of the trip. I stuck to my normal routine of exploration by foot, mapping out a course from Zhongshan Gongyuan, a large park on the west side of the city center, to Wai Tan or The Bund, a pedestrian walkway along the Huangpu River in the east, a distance of about 10 kilometers. As usual, I saw a lot of new things and met some interesting people, but I did sense that breathing became more labored the longer I walked, likely due to the significant amount of particulate and humidity in the air. I normally take maintenance allergy medication during warmer months, but as it had still been quite cold in New Jersey I had not yet started for the spring. I was beginning to make a mental note about my lack of foresight. Like many cities in China, there are emissions from industrial plants on the outskirts, exhaust from the (only somewhat monitored) inner city auto traffic, dust and other particulates from the many and unprotected construction sites, and the above mentioned use of harsh chemicals and building materials. New construction, as well as demolition and rebuilding of old structures, had reached a fever pitch in preparation for the 2010 World Expo in May. The Bund itself was actually a large construction site and completely off limits until finished. I have no doubt this will all look very impressive when finished, though it did put a damper on my day.
The kiss-of-death for me turned out to be a visit with family, when stories, food and germs were shared by all. Since my father-in-law was the first one to have the cold, we thanked him profusely for his generosity. It is difficult to separate out the effect of the cold from the environmental factors and my seasonal allergies in causing the subsequent sinus infection, but either way I was pretty sure that my head was going to explode during the flight back to the US.
At the first visit to the doctor, she prescribed a standard antibiotic treatment for the sinus and recommended restarting allergy medication. Fortunately, all was well on the return trip and we talked about strategies for preventing this in the future. She confirmed that, while the direct effect of some atmospheric gases on the body has not been rigorously studied, it is true that exposure to certain concentrations can make some less tolerant of allergens and other irritants.
So what things might, under certain circumstances, exacerbate my struggle with upper respiratory clarity? Most greenhouse gases, at high enough levels, can have pernicious effects on both the environment and acting directly on humans. The one that jumped out in this case was ground-level ozone (O3). Just to clarify, ozone in the stratosphere is good. It protects us from higher levels of ultraviolet radiation. Ozone at ground-level is a pollutant. It is created by a chemical reaction between another greenhouse gas, nitrous oxide (N2O), and volatile organic compounds (VOC). VOCs are emitted by industrial plants, vehicles, cleaning agents, consumer products, as well as natural sources. Ozone has been linked to upper and lower respiratory problems, and at high enough levels, with cardiovascular problems and premature death. That is why the Weather Channel includes high ozone level alerts with pollen and mold forecasts. There is a vigorous debate over what limit on ground-level ozone would adequately protect humans from these effects, the difference between long and short term exposure, what scientific studies should be done to better understand the full extent of effects on humans and by what mechanism it acts, and who should be responsible for the costs of mitigating it. Most alarming is the frequently overlooked phenomenon of indoor ozone exposure exceeding that of outdoor, due to air seepage and reaction with all of the VOCs we introduce inside our built environments. Here I thought all I needed to do was stay inside and keep the windows closed on bad days. I recommend this article from Environmental Health Perspectives for further reading.
In buildings, such as offices or the aforementioned hotel, achieving LEED certification (Leadership in Energy and Environmental Design) includes management of indoor air quality. Substances with toxic VOCs, such as the new coat of paint, would be screened out in favor of more inert alternatives. Heating, ventilating and air conditioning (HVAC) systems would be designed for optimal air quality at the lowest possible energy usage, and would be sealed off during construction to prevent contamination. As far as outdoor air quality goes, that is a much larger puzzle to solve with many more stakeholders. It will involve scientists, inventors, businesses, governments, and you and me, in the decisions we make about what we buy to put in our homes, as well as how we get to where we need to go when we leave them.