URBAN ORGANIC SOLID WASTE:PRACTICES IN NAIROBI 251
within the city, leading to a vicious circle of deserted farmland, urban expansion and
pollution. The extent of the detrimental effects of these pollutants on humans, animals
and plants has not yet been documented, nor has enough research been undertaken that
is specific for the health implications of organic solid waste reuse in developing cities
such as Nairobi. Among the possible reasons for this may be that: the extent of waste
reuse is not known; disease outbreaks can rarely be traced to specific practices; there
are few experts able to do the research; and developing countries have many other
health research targets (Furedy, 1998).
If concern about health risks of waste reuse in urban agriculture increases, there is a
range of options to reduce risks to workers and consumers (Furedy, 1996). Minimising
the contamination of organic wastes and wastewaters help both health considerations
and economic viability. By obtaining pure organics, many public health risks can be
reduced and the end product is more marketable.
There are two main procedures for obtaining relatively pure organic wastes:
- Separate collection from special generation points (fruits, vegetable and flower
markets; food wastes from restaurants, canteens); and - Separate collection based on segregation of organics by domestic and institutional
waste generators (Furedy, 1998).
Although some studies on the relationship of socio-economic status to morbidity and
mortality have been carried out which suggest a potential relationship between envi-
ronmental agents and lowered health status, the association has not yet been proven,
except in some specific, usually occupational related cases (Sexton et al., 1993).
These issues are not easy to investigate. Sexton et al. (1993) listed a number of the
difficulties involved. These include incomplete knowledge of the aetiology and patho-
physiology of many diseases, a latency period of more than 20 years between exposure
and clinical effects, lack of surveillance systems and methodologies that would accu-
rately track environmental hazards, and the wide range of non-environmental causes
of disease that could be modified by environmental hazards (Mitchell, 1994; Sexton
et al., 1993)
Health effects of composting
Despite using various forms of protective gear, more than a third of the composting
groups, interviewed reported that group members or employees suffered health
problems as a result of their work. These ranged from injury or cuts to headaches, skin
ailments, stomach ailments pains and aches in the body, respiratory problems and
fungal infections. Only half of the composting groups reported that their group
members or employees sought treatment when they got ill as a result of their work.
Health checks of composters have not been done, so other effects such as parasitic
infections are not known.