PROGRAMA DE CIENCIAS MÉDICAS – Area instrumental “Inglés” – Examen Final
Airborne environmental pollutants and asthma
Asthma is a disease in which the resistance to the flow of air in the airways within the lungs increases markedly over short periods of time. Although there are genetic factors which predispose to the development of asthma, exposure to certain environmental factors may contribute significantly to the risk of developing the disease.
With the passing of time, there have been changes in air quality, but in different ways and in different directions! On the one hand, pollution from the burning of coal, which resulted in emissions of sulphur dioxide and particulate matter, has decreased considerably over the last few decades. On the other hand, overall average concentrations of pollution from motor vehicles, notably oxides of nitrogen and some other compounds, have surprisingly not tended to increase in parallel with the increase in numbers of motor vehicles. However, pollution related to the frequency of peaks of traffic, together with their geographical extent, has probably increased. Episodes of pollution from secondary pollutants, notably ozone, produced by photochemical oxidation, have also increased. Moreover, there have also been changes in people's diet, lifestyle, and in homes and other indoor environments. For example, homes have tended to become warmer and much more appealing to cohabitation by dust mites.
Several epidemiological studies show an increased risk of asthma as a direct consequence of occupational exposure to various substances. Some, such as di-isocyanates (used for example in twin-pack spray painting) can cause asthma symptoms in sensitized individuals at concentrations even as low as a few parts per billion, and have even been responsible for a few fatalities. Epidemiological studies of workers exposed to hexachloroplatinates (intermediates in the refining of platinum) suggest that if workers are exposed to high enough concentrations for long enough, they might all develop asthma. Incidentally, occupational epidemiology data clearly show that, for some of the workplace exposures, tobacco smokers are at a higher risk of developing asthma, earlier on, than non-smokers.
1)Translate the lines in bold type
2)Say whether the following statements are True or False (correct the False ones)
a)Pollution resulting from coal burning is not as high as it used to be in the past.
b)An increase in the number of motor vehicles has not resulted in a corresponding increase in pollution levels.
c)There is evidence that smoking increases the risk of developing asthma.
3)Answer these questions
a)Provide a definition for “asthma”.
b)Mention secondary factors that can contribute to the development of the disease.
c)Provide examples of pollutants which can contribute to the development of the disease in the workplace.