Question

study background: in the 1970s, the epa started phasing out the use of lead in gasoline. by the early 1990s, lead was completely removed from gasoline. over time, lead samples in gasoline were collected. also, select people were tested for the presence of lead in their blood. the results from both samples are shown in the following graph. what can be concluded from this graph? removing lead from gasoline in the 1970s was an ineffective policy regulation. there is a correlation between blood lead levels and the use of lead in fuel. people should strongly minimize their exposure to lead while filling their gas tanks. running errands without consolidating trips does not affect lead exposure.

Explanation:

• The first option is incorrect because if lead was removed from gasoline and blood lead levels changed (as per the graph's implied relationship), it was not ineffective.
• The third option about minimizing exposure while filling tanks is not directly supported by the general graph about lead in gasoline and blood levels.
• The fourth option about trip - consolidation is not related to the data of lead in gasoline and blood lead levels.
• The second option is correct as when lead in gasoline (fuel) was phased out (changed), blood lead levels likely changed (a correlation).

Answer:

There is a correlation between blood lead levels and the use of lead in fuel.