Newsletter and Technical Publications
<Municipal Solid Waste Management>
Regional Overviews and Information Sources
Latin America and the Caribbean
2.4 Topic f: Special wastes
Most special wastes are not managed appropriately in
Latin America and the Caribbean; a large proportion enter the MSW stream.
Although legislation on industrial and hospital wastes does exist in a number of
countries in the region, only a few have implemented control programs.
Hazardous industrial wastes are rarely collected by the MSW collection
system. This service is usually provided by private enterprises, which, in some
cases, have specially designed trucks for this purpose. The best cases of
hazardous waste collection systems can be found in Brazil and Mexico. On the
other hand, most collection services are provided in regular trucks, where the
hazard of leakage or accidents is ever-present.
Although some collection of hazardous waste is done separately, industrial
hazardous wastes are frequently disposed of in MSW dumps or other clandestine
dumping sites. For example, in Mexico, which has two operating secure landfills,
an estimated 95% of the hazardous wastes are not accounted for and are
presumably disposed of jointly with MSW.
In a few places in Brazil, certain types of hazardous industrial wastes are
co-disposed with MSW in a technically managed way so that environmental impacts
are controlled. However, co-disposal is highly controversial and is not being
promoted in most countries in the region.
Hospital wastes have received more attention than industrial wastes in the
region, though much work is still needed to achieve proper management of these
wastes. Waste pickers in dumps are exposed to needles and other dangerous
hospital wastes. There are also cases of exposure to radioactive materials from
discarded hospital materials.
A large part of the work done on hospital wastes is related to
characterization. Thus, there is a good understanding of the sources of
pathogenic, chemically hazardous, and regular solid wastes within a health
facility. However, there is not agreement on methods for adequate treatment and
disposal of such wastes. Some authorities support the separation of hazardous
hospital wastes at the source and the subsequent differential treatment of such
wastes, according to the specific hazards presented. Others believe that
segregation at the source is very difficult and that the risk of hazardous
materials entering the MSW stream is too great, so that all wastes should be
collected and disposed of as hazardous hospital wastes. This is the case in the
state of Sao Paulo, Brazil, where regulations require that all hospital wastes
be collected and transported to a municipally owned, centrally located
incinerator. In this case, no on-site separation of hospital wastes is allowed.
Except for the case of Sao Paulo, legislation typically requires that wastes
be treated by on-site incineration. However, few hospitals have incinerators,
and the ones that have them do not operate well. As a result, solid waste
authorities, with the aim of providing a solution, sometimes allow disposal in
specially designed cells within sanitary landfill facilities.
Although not much has been written on demolition wastes in the region, they
are generally a problem due to their volume and the cost of transporting them.
There are not specifically designed landfills in the region for these wastes. In
many places demolition wastes are reused for land reclamation in coastal areas
or quarries. In Mexico City, much of the demolition waste after the earthquake
was used to fill up water-logged areas of the city. These wastes are also used
as a base for road construction.
Tires, oils and batteries are usually recycled, though the recycling process
is not always environmentally adequate. Recycled oil can be marketed, even
though quality control is often nonexistent, because it is inexpensive. In the
case of waste oils, filter residues are often disposed of in the sewers.
Batteries are often taken to small-scale foundries which do not have emissions
control systems and are often located in residential areas.
Since only a few cities have wastewater treatment plants there is little
sewage sludge disposal. In general, where sewage sludges are generated, they are
disposed of by the rivers or on the land. In Brazil, sewage sludges are disposed
of on farmland.