Lungs correllation

Question 1

The scientists concluded that substances in the air from vehicle exhausts did not cause the increase in asthma between 1976 and 1980. Explain why.

how to answer question

Answer 1

Correlation does not mean that there is a causal relationship;

1. Do not accept casual
2. May be some other factor / named factor associated with vehicles and asthma / producing rise in both;
3. (After 1980) asthma continues to rise but exhaust concentration falls / negative correlation (after 1980);