Contrast point source pollution and nonpoint source pollution.

The point source and nonpoint sources can be differentiated:

1. Source of origin: In point source pollution the pollutants are originated from a identifiable and single source whereas in nonpoint pollution, pollutants originate from different sources and they get mixed therefore, the source of origin cannot be identified.

2. Control and prevention: As, point source pollutants originate from a single source they can be track back at their origin sites and their synthesis can be prevented whereas nonpoint pollutants originate from different sources their synthesis cannot be prevented.

3. Dilution level: The point source pollutant originate from a single source therefore remains in the concentrated form near the source of origin whereas nonpoint source pollutants originate from different sources therefore remain in diluted form.  

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.