Why do you think people became concerned with environmentalism in the 1970’s?

In the 1960s and 1970s, the environmental movement focused its attention on pollution and successfully pressured Congress to pass measures to promote cleaner air and water. In the late 1970s, the movement increasingly addressed environmental threats created by the disposal of toxic waste.

Information source:

https://www.encyclopedia.com/earth-and-environment/ecology-and-environmentalism/environmental-studies/environmental-movement

Please don't report for link. This is my source of information.

answer; the smaller of the two reciprocal products of translocated chromosomes is lost; after several cell divisions, only the larger of the two translocated chromosomes remains,its reciprocal is lost;