A、Slightly polluted areas. B、Heavily polluted areas. C、Urban areas. D、Rural areas. A

(19)People who live in areas with polluted air increase their risk for developing high blood pressure, a leading risk factor for the development of heart disease. Known as hypertension, the high blood pressure study is the largest of its kind to establish the deadly link.
    A recent study looked at hypertension in 41,000 people in five different countries—Norway, Sweden, Denmark, Germany and Spain—for five to eight years.
     (20)It is part of the long-term "Europe Study of Cohorts for Air Pollution Effects," known as ESCAPE, which focuses on health problems associated with pollution.
    At the hypertension study, beginning in 2008, none of the participants reported having high blood pressure or taking medicine to control it. By 2011, 6,200 people reported having developed hypertension and started taking blood-pressure lowering drugs. Most lived in urban areas, where air pollution levels are usually highest.
    Air pollution is measured in micrograms of particulate matter per cubic meter. The researchers found that for every five micrograms per cubic meter of particulate matter, hypertension increased by one-fifth or 22 percent in people living in the most polluted areas.
     (21)Epidemiologist Barbara Hoffmann, who works for the Centre for Health and Society at Heinrich-Heine University in Germany and led the study, says many of these cases of high blood pressure could be prevented.
    " So this is a very important result if you can see that something that you can actually change. I mean we can actually reduce air pollution, can have such an influence on such an important health outcome," said Hoffman.
    The findings were published in the European Heart Journal.
     (22)Hoffmann says researchers will next study areas of where pollution is low, looking at the health effects of cleaner air.
    " But this is of course important in terms of regulation because you would like to regulate the air pollution down to a level where you do not see any health effects anymore. So, therefore it is really important to look at areas of low exposure and see how far down can you go until you do not see any effects anymore," said Hoffman.
    It is believed that air pollution leads to health problems by causing lung inflammation that spreads throughout the body, eventually leading to blood vessel and heart damage.
Questions 19 to 22 are based on the recording you have just heard.
19. According to the speaker, what will increase the risk of high blood pressure?
20. What does ESCAPE focus on?
21. What does Barbara Hoffmann say about high blood pressure?
22. According to Hoffmann, which area will researchers study next?