scientific explanations for the following facts. Express the concepts,
facts, and chain of logic clearly. Draw supporting figures if useful.
in the tropical areas have higher chance of developing cataracts
in their eyes than people in the temperate zones
A cataract is the eye lens turning opaque, leading to loss of sight.
This happens because of changes in the proteins in the lens. Visible
light at most ordinary levels can not cause these changes, but ultraviolet
light can. Solar radiation contains ultraviolet. Much of this is filtered
by the ozone layer in the stratosphere. However, some ultraviolet
does get through. The tropics receive more direct sunlight, and therefore
a greater intensity of solar radiation. So, the amount of ultraviolet
filtering through the ozone layer is higher in the tropics. Thus,
people in the tropical zone have more ultraviolet falling on their
eyes, and therefore have a higher chance of developing cataracts.
leaves appear green to our eyes.
give rise to "holes" in the ozone layer.
is smog in Los Angeles.
in cities with higher traffic density have a greater chance of developing
respiratory problems than people who live in well-ventilated houses
in pristine areas.
and matter are conserved (as far as we know), yet we are concerned
about "running out of energy".
contributes to global warming.