A total of 850 insulation workers employed between 1940 and 1945 was identified from the personnel records of three large insula
tion manufacturing plants in the Midwestern U.S. in 1980. During the period 1940-1980, 28 deaths from lung cancer were discovered among the workers. Only eight lung cancer deaths, however, were reported among a comparable group of 800 coworkers who did not work with insulation during the same time period. The investigators had hypothesized that exposure to the insulation material increases the risk of lung cancer. Required:
Which epidemiology study design best represents this description?
A Retrospective cohort study is a type of observational study or research. The investigator looks back in time self-report data to see if the risk of disease was different between exposed and non-exposed patients.
The distinguishing feature, that help in identifying it, of this study is that the investigators conceive the study and begin identifying subjects after results have already been found or developed in some of the subjects.
I believe that they are becoming more concerned for zoonotic disease because it is becoming more and more common for these animal transmitted disease to spread, such as ringworm or hookworms. The factors that would make these more of a threat would likely be the amount of people with animals or the other animals or people their animals are around or not taking your animal to the vet upon signs of seeing symptoms of declining health.
Answer: A steam engine is an external combustion engine (ECE) in which the fuel is combusted outside of the engine, unlike an internal combustion engine (ICE) in which fuel is combusted inside the engine. ECEs have a lower thermal efficiency, but carbon monoxide production is more readily regulated.
