Which of the following is the most serious effect of water pollution for humans?
a. infectious diseases
b. algal blooms
c. toxic food chain effects
d. low-oxygen water

The option which is most serious effect of water pollution for humans is infectious diseases.

Explanation:

Infectious diseases are disorders which are caused by organisms like microorganism, viruses, fungi or parasites. Several organisms live in and on our bodies.

Some of these water-borne diseases square measure enteric fever, Cholera, paratyphoid, Dysentery, Jaundice, amoebiosis and protozoal infection. Chemicals within the water even have negative effects on our health. Pesticides will harm the system and cause cancer owing to the carbonates and organophosphates that they contain.

the more fit you are, the faster the recovery. your heart rate drops most sharply in the first minute after you stop exercising; it should then fall about 20 beats a minute—a drop of less than 12 beats a minute is considered abnormal. this “recovery heart rate” is measured as part of an exercise stress test.