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are polluted by non-collected waste or leachates produced
at dumpsites. This same water is used for drinking, cooking,
cleaning or for irrigating crops. The disposal of mixedmunicipal
waste containing hazardous medical and household waste,
can cause further pollution.
Other public health issues from dumpsites include the
proliferation of disease-vectors such as rats, mice, flies and
other pests that feed on waste. Often, domestic animals feed
on waste in open dumping sites, a common practice in many
cities in developing countries. These animals also act as vectors,
especially of parasitic diseases. The weather and atmospheric
conditions at higher altitudes, however, hinders the proliferation
of mosquitoes, insects or other species of pests common in
lowland cities with more tropical climates.
Nonetheless, the effects of open dumping can be particularly
harmful to sensitive mountain ecosystems. Furthermore, the
effects of dumping waste in river gorges has the potential
to impact very large populations as the river waters are used
by millions of people living on the floodplains. Uncontrolled
burning is often used as an easy way of getting rid of waste
or reducing the volume of waste. However, the smoke
produced by burning waste creates risks because of the
generation of particulate matter and other hazardous gases
emitted into the atmosphere.
Air pollution is affected by changes in altitude; incomplete
fuel combustion occurs when there are lower levels of oxygen,
leading to higher amounts of suspended particles, otherwise
known as soot (EPA, 1978). The effects of altitude are not
always taken into account in setting standards for air quality.
For example, current air quality standards for particulate matter
(PM) in some high-altitude cities (El Alto, Medellin and Mexico
City) are thought to underestimate the important effects of
altitude (reductions in temperature and pressure), which might
explain why there is a rising prevalence of asthma and allergies
in high-altitude urban areas in Latin America (Bravo Alvarez
et al., 2013).
The people most likely to be at risk are those living in peri-
urban, low-income areas who do not have an adequate
collection service, people living in areas adjacent to open
dumping sites, especially children and the elderly, and
personnel working for urban cleansing services (Scheinberg,
Wilson and Rodic-Wiersma, 2010).
Air pollution over Mexico city.
Photo
©
iStock/jcarillet