Question

Mud from a lake on an uninhabited wooded island in northern Lake Superior contains toxic chemicals, including toxaphene, a banned pesticide for cotton that previously was manufactured and used, not in nearby regions of Canada or the northern United States, but in the southern United States. No dumping has occurred on the island. The island lake is sufficiently elevated that water from Lake Superior does not reach it.

The statements above, if true, most strongly support which of the following hypotheses?

(A) The waters of the island lake are more severely polluted than those of Lake Superior.
(B) The toxaphene was carried to the island in the atmosphere by winds.
(C) Banning chemicals such as toxaphene does not aid the natural environment.
(D) Toxaphene has adverse effects on human beings but not on other organisms.
(E) Concentrations of toxaphene in the soil of cotton-growing regions are not sufficient to be measurable.

Answer 1

The hypothesis most strongly supported is that the toxaphene was carried to the island in the atmosphere by winds. This is consistent with evidence that toxic chemicals, including pesticides, can travel through the atmosphere and affect distant ecosystems.

Step-by-step explanation:

The hypothesis most strongly supported by the given statements is that the toxaphene was carried to the island in the atmosphere by winds (Option B). Given the fact that toxaphene, a banned pesticide, is found in the mud of a lake on an uninhabited wooded island which does not have direct water contact with Lake Superior and is distant from where the chemical was used, atmospheric transport seems to be the plausible explanation for the presence of toxaphene.

The information provided exhibits how toxic chemicals can disperse and affect regions away from their points of origin. For instance, brominated flame can accrue in whales deep in the ocean, and pesticides can be found in forest barks globally. Moreover, pollutants like PCBs can biomagnify up food chains, implicating that chemicals can be transported through air and water, impacting distant ecosystems.

Considering these mechanisms of environmental contamination, alongside the fact that no local dumping occurred and the existence of atmospheric transport of pollutants described in various studies, it is reasonable to conclude that the toxaphene reached the island through the atmosphere.