Question

1. although ______ is regulated as a secondary contaminant because precipitates of the metal can cause cloudy-looking water, this contaminant may interfere with absorption of fluoride in the gastrointestinal tract and may decrease the absorption of calcium, iron, and cholesterol.

a. aluminum
b. zinc
c. silver
d. manganese

1. ______ may be caused by aromatic, polyhydroxy, methoxy, and carboxylic acids, as well as fulvic and humic acid fractions, and the presence of metals such as copper, iron, and manganese. changes to these levels may provoke citizen complaints.

a. taste
b. odor
c. color
d. laxative effects

Explanation:

1. Aluminum is classified as a secondary drinking water contaminant; its precipitates cause cloudy water, and it interferes with absorption of fluoride, calcium, iron, and cholesterol as described.
2. Organic acids like fulvic/humic acids and metals such as copper, iron, manganese are known to cause discoloration in water, which often leads to public complaints about water appearance.

Answer:

1. a. aluminum
2. c. Color