| A wide variety of forces and stresses act
as determinants of environmental health status in urban settings. Negative aspects of
population size, urbanization, poverty and inequity, technical and scientific
developments, levels of economic development, and patterns of consumption and production,
all have the potential to overwhelm the coping mechanisms of the natural environment,
often with serious consequences for human health (WHO, 1997). |
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| Threats to environmental health status |
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| In South Africa the high demand for shelter, infrastructure and basic
social services coupled with high pollution levels, has serious health implications for
urban populations. Health status is further threatened by high levels of poverty and low
levels of environment and health literacy. Past political and economic policies have
played a major role in the current inequitable spatial distribution of environmental and
health status in urban settings. Consumption patterns of affluent sectors of the South
African society are unsustainable and have significant environmental and health impacts.
These include vehicular transport, the production of excessive waste and high levels of
resource consumption. |
| Drinking water and sanitation |
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| It is estimated that an average of 2.9% of people in informal settlements
in the CMA do not have access to water supplies within 50 metres of their place of
dwelling. In areas such as Khayelitsha, this proportion may increase to over 5% (Baron et
al, 1995). The utilisation of insufficient quantities of water has a negative impact
on domestic and personal hygiene practices, with the potential for spread of disease.
Despite communal supplies of safe water, water quality has been found to deteriorate
through storage and handling practices. Bacteriological examination showed that around 10%
of samples examined exceeded national guidelines for E. coli (Genthe et al,
1997). As water supplies to communities have improved, levels of diarrhoeal disease have
been decreasing in the Cape during recent years. From 1 July to 1 November 1998, 10 271
cases of diarrhoea were recorded at clinics throughout the CMA (Western Cape Provincial
Health Department). A lack of, or
inadequate sanitation services in certain parts of the CMA has led to extensive faecal
contamination of the local environment (Samson, 1997) as well as pollution of rivers and
streams in the vicinity. Under these conditions, the potential for direct infection, as
well as the contamination of food and drinking water supplies, is high. Diseases
associated with faecal contamination include cholera, hepatitis, typhoid, dysentery,
poliomyelitis and helminthic (worm) infections (von Schirnding et al, 1992).
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| Surface water pollution |
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| Untreated human waste,
industrial discharges and agricultural run-off may increase loads of faecal pathogens,
toxic chemicals, pesticides and fertilisers in surface water. Where surface water is used
for drinking, washing, cooking and recreational purposes, users may be at risk of
contracting a wide range of serious diseases. Figure 1 shows
levels of Escherichia coli at selected river monitoring sites in the CMA.
Standing water in informal and squatter settlements is a common feature due
to the lack of adequate storm water drainage. When contaminated with faecal pathogens it
poses a health hazard, as it is associated with gastro-intestinal diseases. |
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| Figure
1 |
| Escherichia coli
levels at selected CMA river monitoring sites (Source: Mathee et al,
1998) |
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| Increasing urbanisation, and associated
disposal of wastewater into marine waters, has raised concerns with respect to potential
health impacts on beach-goers. |
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| Solid waste |
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| Uncollected waste often serves as a breeding ground for rodents and other
disease carrying vectors, particularly in informal and squatter communities. In addition
to raised risks of gastro-intestinal and other diseases, open waste has been associated
with injury, suffocation, poisoning and death amongst scavengers and children playing in
the vicinity. In 1995, approximately 6% of dwellings in the CMA had no access to waste
removal services (CCS, 1996 as cited in CMC, 1999a). Waste disposal options such as
landfilling and incineration hold negative environmental consequences. During recent
years, waste scavenging at landfill sites has emerged as an environmental health risk
(Khan, 1996). |
| Air pollution |
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| Exposure to air pollution
poses short-term and chronic health risks. Health effects associated with exposure to air
pollution vary widely and range from minor ailments such as eye, nose and throat
irritation and headaches, to serious conditions such as the aggravation of asthma, chronic
bronchitis, reduced pulmonary function, chronic obstructive pulmonary disease and death. Figure 2 shows respiratory symptoms to be the most commonly
occurring health concern in two informal settlements in the CMA (Mathee and von
Schirnding, 1996). The use of
paraffin as a source of energy represents not only an environmental hazard, in the form of
air pollution, but also a very important health hazard. |
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| Figure
2 |
| Ill health symptoms
in two Cape informal settlements (Source: Mathee et al, 1998) |
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| In general, women and children are those
most at risk from incidents of trauma and even death from paraffin poisoning, burns and
fires (Eberhard and Trollip, 1994). |
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| Housing and shelter |
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| The quality of living environments is well-known to be one of the most
powerful determinants of health and has the potential to reduce life expectancy.
Inadequate housing is associated with a wide range of physical, psychological and social
ill effects (Mathee and von Schirnding, 1996). Housing quality in the CMA varies widely,
from suburbs with high quality formal housing to informal/squatter housing settlements.
Overcrowded housing has the potential to promote the spread of communicable diseases such
as tuberculosis. The number of cases of pulmonary tuberculosis reported in the City of
Cape Town has increased steadily during the past three decades (City of Cape Town,
1995/96). According to the Western Cape Provincial Health Department records, there were
367 deaths due Tuberculosis in the Cape Metropolitan Region in 1997. Acute respiratory infections have gained importance
as a cause of childhood morbidity and mortality (City of Cape Town, 1995/96). Between July
and December 1998, 27 432 cases of acute respiratory chest infection in children were
recorded throughout the CMA.
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| Food contamination |
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| Food provides an ideal medium for the growth and spread of a wide range of
pathogens including cholera, botulism, shigellosis and typhoid fever. In the CMA, the
informal food trade and the informal slaughtering of animals poses a public health threat
due to inadequate hygiene. In informal settlements, the absence of refrigeration
facilities for the storage of perishable foods is an added health risk. Table 1 shows number of
bacteriological exceedances in pasteurised packaged and bulk retail milk from 31 January
to 31 December 1998. Bacteriological standards were exceeded much more frequently in milk
sold via bulk tanks compared to packaged milk.
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Table 1 |
Number of
bacteriological exceedances in pasteurised packaged and bulk retail milk (1998) |
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| Bacteriological measurements |
Number of times standard exceeded for pasteurised packaged milk
(3 020 samples taken) |
Number of times standard exceeded for pasteurised bulk retail milk
(742 samples taken) |
| Total count
(standard plate count) (exceeded 50
000 colony forming units per 1ml) |
55
(1.8% of samples taken) |
187
(25.2% of samples taken) |
| Coliform
bacteria (exceeded 10 coliform
bacteria per 1ml) |
568
(18.8% of samples taken) |
573
(77.2% of samples taken) |
| Escherichia
coli (present) |
39
(1.3% of samples taken) |
86
(11.6% of samples taken) |
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(Source: CMC, 1998a)
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| Environmental lead exposure |
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| Childhood exposure to environmental lead has been associated with a wide
range of health effects, including decrements in intelligence quotients (IQ), anemia,
shortened concentration spans and poor school performance. Studies conducted in the Cape
Peninsula have indicated that certain groups of children may be at risk of raised blood
lead burdens, for example, children attending schools in close proximity to heavily
trafficked roads and those who live in dilapidated and dusty homes (von Schirnding et
al, 1991 and Kibel et al, 1993). |
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