Researchers collected data to examine the relationship between pollutants and pre-term births in Southern California. During the study air pollution levels were measured by air quality monitoring stations. Specifically, levels of carbon monoxide were recorded in parts per million, nitrogen dioxide and ozone in parts per hundred million, and course particulate matter (PM_10) in µg/m3. Length of gestation data were collected on 143,196 births between the years 1989 and 1993, and air pollution exposure during gestation was calculated for each birth. The analysis suggested that increased ambient PM_10 and to a lesser degree, CO concentrations may be associated with the occurrence of preterm births. a. The paragraph above describes an
A. Observational Study
B. Experiment
b. The cases in this research are
A. Each birth between 1989 and 1993
B. Each type of pollution measured by air quality monitoring stations
C. Each year between 1989 and 1993
D. Air pollution exposure during gestation
c. What is the research question?
A. How much air pollution is there in Southern California?
B. How prevalent was preterm birth during the years 1989 to 1993?
C. Are preterm births associated with air pollution levels?
D. How can expectant mothers avoid air pollution?
d. What is the population of interest?
A. All human babies
B. All years for which air quality has been measured
C. All environmental pollutants
D. All air quality monitoring stations
e. What is the sample?
A. The pollution measurements for the 4 pollutants
B. Al air quality monitoring stations
C. The 143,196 births
D. The years between 1989 and 1993