麻豆传媒

A session at the recent American Thoracic Society (ATS) annual meeting focused on the effect that the environment has on lung health. It included a presentation from Gregory P. Downey, MD, executive vice president of academic affairs at National Jewish Health in Denver, on the consequences of a warming climate for patients with airway diseases such as asthma and chronic obstructive pulmonary disease.

In this exclusive 麻豆传媒 video, Downey, who is also the immediate past president of ATS, goes over a few of the points he made in his presentation.

Following is a transcript of his remarks:

So there's some obvious things. as the temperature increases we get these temperature extremes. People don't tolerate extremes of temperature. And if you saw the news in the last few days, Phoenix was going to reach 115°F. I think some of the Middle Eastern countries, going to Celsius, now it's up to 50°C.

And when people are exposed to those environments, they have a difficult time temperature regulating. You can't sweat enough to make up for that heat. And the body temperature's 37°C. And if it's 50°C outside, your body starts to warm up. That dries out the respiratory secretions and causes many other changes -- heat stroke, etc.

In addition, the warming temperatures have increased the amount of pollen that is produced by trees and also the duration of the pollen season. And this has been mapped pretty carefully. And if you plot carbon dioxide and surface temperature versus pollen levels, it's a pretty linear relationship. And the problem is that we are all now faced with these increasing pollen concentrations and duration. And this is one of the triggers for allergic diseases -- so sinusitis, asthma -- and this has led to a significant increase in the incidence of asthma around the world.

Looking into the future, although it's still, I'd say, not completely settled, people who have chronic poorly controlled asthma are predisposed to getting chronic obstructive lung disease as they age. And we are now seeing an increased incidence of chronic obstructive pulmonary disease in patients who've never smoked a day in their lives, and have not been exposed to at least abnormally high concentrations of secondhand cigarette smoke. So the thought is that this is a consequence of other exposures. So this first example of how climate change is driving respiratory health problems relates to the increased pollen, the allergic diseases, and in the future, chronic obstructive pulmonary disease.

The other thing is that as the temperature increases and the conversion of oxygen in the atmosphere to ozone is increased. And so this is another interaction -- a complex interaction between the warming temperatures and then another pollutant, ozone, which again then interacts with the particulate matter and the allergens to increase the severity of lung disease.

People have looked at the consequences of exposure to particulate matter and other byproducts of combustion, nitrogen oxides, and ozone. And it is very clear that exposure, even before birth, can affect the developing fetal lungs, and that in the first few years of life where the lungs of humans are still developing, increased exposures also have been shown to cause abnormalities of development of the lung. And one of the thoughts right now is that given the totality of these exposures, many infants and young children will never retain their full pulmonary function.

So normally, after birth, we achieve our full lung capacity somewhere between 18 and 20 years. But if there are high levels of exposure to pollutants, many of those people will never attain their full lung function, and therefore they start off at a disadvantage in adulthood and with other exposures, with infections, they are much more susceptible to getting severe consequences of what normally could be dealt with by a normal adult with a normal lung.

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