Comparison of indoor air quality in electrified and un-electrified dwellings in rural South African villages.

UNLABELLED: A feasibility study was undertaken to assess the suitability of South African rural villages due to be electrified, for the purposes of undertaking a large-scale study of the impact of reductions in indoor air pollution on acute lower respiratory infections. As part of the feasibility study, quantitative assessments of indoor air pollution in non-electrified and electrified dwellings were performed. Concurrent measurements were made of levels of respirable particulate matter (RSP-stationary), and carbon monoxide (CO) (personal on children <18 months), as well as a stationary co-located with RSP) over a 24-h period in 52 un-electrified and 53 electrified dwellings. The proportion of dwellings with a detectable 24-h concentration of RSP was significantly higher in un-electrified (48.1%) than electrified dwellings (24.5%) (chi(2) = 6.30 on 1 d.f., P = 0.012). In addition a Kruskal-Wallis test (adjusted for ties) showed that the distribution of RSP differed between un-electrified and electrified areas (Kruskal-Wallis chi(2) = 8.20 on 1 d.f., P = 0.014). In those dwellings where some RSP was detected, the amount was on average higher in the un-electrified areas (mean 162 microg/m(3), median 107 microg/m(3)) than in the electrified areas (mean 77 microg/m(3), median 37.5 microg/m(3)). Stationary (kitchen CO) levels in un-electrified dwellings ranged from 0.36 to 20.95 p.p.m. However, in electrified dwellings, kitchen levels ranged from 0 to 11.8 p.p.m. When mean concentrations of CO were compared between electrified and un-electrified dwellings using a two-sample t-test (on log-transformed data), there was overwhelming evidence (P = 0.0004) that the mean level of log (CO) in the kitchen was higher in the un-electrified areas (1.25 vs. 0.69) and also overwhelming evidence (P < 0.0001) that the mean level of log (CO) on the child was higher in the un-electrified areas (0.83 vs. 0.34). Of importance in terms of both policy and for a potential future large-scale study, is that measurable significant differences in indoor pollutants between electrified and un-electrified dwellings during summer were found in spite of only partial transition to electricity use for cooking in electrified villages. PRACTICAL IMPLICATIONS: It is estimated that at least two-thirds of all households in the developing world are still primary dependent on biomass fuels and coal. This situation applies to 59% of rural households in South Africa. In the last decade a program of providing electricity to three million homes has been underway in South Africa. Among others this intervention aims to reduce exposure to pollutants from burning biomass fuels and reduce detrimental health effects, especially in young children. This study provides scientific evidence that electrified homes in South African villages have lower levels of air pollution (RSP and CO) relative to their non-electrified counterparts.

A survey of blood lead levels among young Johannesburg school children.

Studies conducted around the world have established beyond doubt that elevated childhood blood lead levels may lead to detrimental health effects. Research has shown that certain groups of South African children are at particular risk of elevated blood lead levels. Johannesburg is the largest urban complex in southern Africa, with a population of around 3 million and extensive industrial and manufacturing activity. Among the challenges posed in the city are rapid urbanization, extensive poverty, and inequity. Little information on the blood lead distribution of Johannesburg children is available. This study was undertaken to determine blood lead levels among children living in three areas of Johannesburg: inner city suburbs and the low-income townships of Alexandra and Westbury to the north and west of the city center, respectively. The results indicated that blood lead levels ranged from 6 to 26 micro g/dL, with a mean level of 11.9 micro g /dL. The blood lead levels of 78% of children equaled or exceeded 10 micro g/dL, the current international action level. Maternal educational status, the presence of smokers in the home, and living in an informal dwelling were among the factors associated with elevated blood lead levels.

Environmental lead exposure: a public health problem of global dimensions.

Lead is the most abundant of the heavy metals in the Earth's crust. It has been used since prehistoric times, and has become widely distributed and mobilized in the environment. Exposure to and uptake of this non-essential element have consequently increased. Both occupational and environmental exposures to lead remain a serious problem in many developing and industrializing countries, as well as in some developed countries. In most developed countries, however, introduction of lead into the human environment has decreased in recent years, largely due to public health campaigns and a decline in its commercial usage, particularly in petrol. Acute lead poisoning has become rare in such countries, but chronic exposure to low levels of the metal is still a public health issue, especially among some minorities and socioeconomically disadvantaged groups. In developing countries, awareness of the public health impact of exposure to lead is growing but relatively few of these countries have introduced policies and regulations for significantly combating the problem. This article reviews the nature and importance of environmental exposure to lead in developing and developed countries, outlining past actions, and indicating requirements for future policy responses and interventions.

A study of the distribution of urban environmental lead levels in Cape Town, South Africa.

Epidemiological studies which have attempted to quantify the relationship between environmental lead and blood lead levels have been beset by numerous methodological problems, one of which has been the difficulty in assessing environmental exposure to lead. In Cape Town, South Africa, a comprehensive environmental lead monitoring programme was instituted in an inner city suburb where a blood lead screening study was in progress. The objective of the study was to examine the spatial and temporal variation in environmental lead levels, and to examine the role of potential influencing factors such as traffic. Results revealed substantial intra-urban variations in air lead levels, with annual means varying from less than 0.5 to over 2 micrograms/m3 at individual sites. Traffic density and the distance from heavily trafficked roads were important influencing factors within the area. Considerable seasonal as well as daily variations in air lead levels were also documented, and air lead levels were positively associated with dust lead levels. The spatial and temporal variations in environmental lead have implications for air monitoring strategies and epidemiological studies concerned with the relationship of exposure to lead and the health impact on populations. Micro variations in exposure need to be taken into account assessing exposure to environmental lead in epidemiological studies, in light of the considerable variations which may occur.

The Greater Johannesburg Healthy Foods / Markets Programme.

PIP: This article discusses the World Health Organization's (WHO) Healthy Cities Project's (HCP) Healthy Foods/Markets program in Johannesburg, South Africa, among food vendors (FVs). Food contamination is a major contributor to illness, a compromised nutritional status and less resistance to disease, and loss of productivity. Health risk is related to the potential of food to support microbiological growth. Foods can have a high or low health risk. Food risk is related to food type, pH, method of preparation, water availability, handling, exposure temperature, and holding time. Food vending has increased in South Africa, and may employ 6-25% of the labor force. Street food is exposed to climate and temperature, unsafe water supplies and sanitation, and pests. A study conducted among 116 FVs in Johannesburg, assessed the microbiological food quality and potential risks. Formal FVs were less likely to be women and had more vending experience than informal ones. All food from informal FVs was hot, while food from formal FVs tended to be cool. 73% of formal FVs stored leftovers for sale the next day. FVs used some precautions in food preparation. 15% of street FVs, and 13% of formal FVs, had contaminated foods. Formal traders had better hygiene practices, but greater storage that would contribute to contamination. Street FVs need access to safe, ample supplies of water, sanitation, and waste disposal mechanisms. Authorities will be implementing the WHO Hazard Analysis Critical Control Point for low-cost, effective surveillance of street foods.^ieng

Environmental planning and management in Greater Johannesburg.

PIP: This article describes the actions among urban environmental, management, and development planners in Greater Johannesburg, South Africa. Initiatives, such as the Healthy Cities Project and Model Communities, are being integrated into an environmental management and development approach that attains the goals of Agenda 21. Greater Johannesburg has housing shortages and homelessness. Priority needs include the areas of housing, water, electricity, public transportation, and sanitation. Clean water and air are inequitably distributed. Other key environmental problems include illegal dumping, inadequate waste disposal, poor environmental hygiene in overcrowded inner city areas, lack of open spaces, flooding, and water scarcities. The newly formed metropolitan authority offers opportunities to improve coordination and integration of environmental problems. Stakeholders from government at all levels, politicians, nongovernmental organizations, and the business sector formed an intersectoral, interdepartmental environment management committee in 1995. Stakeholders will integrate Agenda 21 within broader urban development plans and processes. The executive committee and the full council approved a set of guiding principles on environmental policy and an administrative framework for management. Four workshops were held to ensure a participatory consultation process in 1995. The WHO Collaborating Center for Urban Health will be used to facilitate the work of the Greater Johannesburg Metropolitan Council. Changes are being made in the way local governments work.^ieng

A new approach towards environmental management in greater Johannesburg.

PIP: This article describes the efforts of the South African Greater Johannesburg Transitional Metropolitan Council to more equitably distribute resources to areas of greatest need and most severely affected by environmental damage. The Council increased coordination within the metropolitan government to address local environmental problems and increased awareness and expertise in environmental management among nongovernmental groups and individuals within government and development institutions and within local planning and environmental forums. The Council also created opportunities to expand environmental data collection in Johannesburg and to reintroduce indigenous nature and wildlife. Environmental development initiatives were established as early as 1990. The city initiated a Health Cities Project in 1993. The Council established an Environmental Management Committee, which makes recommendations to the Executive Committee and ensures a sustainable, supportive, and healthy environment. A preliminary situational analysis revealed data inadequacies, lack of coordination, lack of enforcement, and lack of public awareness. Working groups were established to deal with pollution, sanitation, food safety, hazardous substances, and chemical safety. The environmental management committee formed viable partnerships with key health and medical people and joined the Global Environmental Monitoring Systems (GEMS) program of WHO. The committee plans to develop a new administrative framework, environmental policy and management system, state of environment reports, uniform legislation, and other efforts.^ieng

The health effects of exposure through swimming in South African marine waters: an overview.

PIP: This study evaluated the health effects of exposure to pathogenic microorganisms in South African marine waters during 1990-94. About 20% of South Africa's coastline is used for recreational purposes. The prospective study was conducted on 4 beaches and a tidal pool in the Western Cape Province in 1990. The sample included about 16,000 participants willing to provide information at the time of contact and at a follow-up date. The aim was to assess the health risks, to establish the relationships between swimming and water quality and health outcomes, and to recommend appropriate microbiological indicators. Prospective trials were discretely carried out during the peak holiday season. The trials relied on methods established by Cabelli (1982) and endorsed by the US Environmental Protection Agency (EPA) in 1986, and the World Health Organization in 1991. Water quality samples were obtained on recruitment days for fecal coliforms, E. coli, fecal streptococci, staphylococci, and coliphages. Findings indicate that the microbiological quality of the water on the 4 beach sites complied with both existing South African standards and US EPA guidelines. The tidal pool showed signs of pollution with fecal coliforms, fecal streptococci, and staphylococci. Water quality varied on different days. Further analysis is being conducted on the different levels of water quality. All sites showed an increased health risk for swimmers compared to nonswimmers. Site 2 showed a statistically significant risk. A prior pilot study found some evidence of a relationship between swimming-related illness and water quality.^ieng

Towards a higher priority for health on the development agenda.

Over the last few years major international agencies (particularly the World Health Organisation and the World Bank) have increasingly recognised that investing in health is crucial for development. Development policies have the potential to enhance or impede progress in achieving Health for All. At the macro-economic level it is broadly recognised that the state of the economy of a country has a strong influence on its health level. The growing number of the population below the poverty line in sub-Saharan Africa is expected to have a substantial impact on health in the future. Further, structural adjustment programmes' impact on health has yet to be adequately evaluated. Rapid population growth in sub-Saharan Africa needs to be innovatively addressed as a matter of extreme urgency. The education of women is strongly related to child survival. Over the next few years the prospects for global disarmament are increasing. Options for using both the technology, financial savings, and personnel for improving health need to be investigated. A broader range of policy options for health needs to be considered by governments. A greater focus on information, education, and communication for health is needed that draws upon both the private and the public sector; greater use of regulation and legislation as solid policy instruments, for example, for pollution control, and banning tobacco and alcohol advertising, is required. Financial strategies using a combination of taxes and subsidies have not been adequately used in developing countries. The previous emphasis on urban-based expensive hospitals has proved to be inappropriate, resulting in severe inefficiency and inequity in the health systems of developing countries. Greater attention must be given to funding those areas with a high potential for positive externalities and that yield public goods. The final policy instrument involves using research to extend the options for intervention choice.

PIP: The growing number of the population below the poverty line in sub-Saharan Africa is expected to have a substantial impact upon health in the future, while the impact of structural adjustment programs upon health has yet to be adequately evaluated. Major international agencies such as the World Bank and the World Health Organization are increasingly recognizing that investing in health is crucial for development. Options for using technology, financial savings from increasing global disarmament, and personnel for improving health need to be investigated, while a broader range of policy options for health needs to be considered by governments. Information, education, and communication strategies for health which draw upon both the public and private sectors must be put in place. Moreover, health-related regulation and legislation are called for with regard to issues such as pollution control and tobacco and alcohol advertising. Combining taxes and subsidies has not been adequately used in developing countries. There is also a great need to reorient away from hospital-based health care systems. The authors look at the emerging consensus on the need to invest in health, the national and international impact of policies which affect health, and their implications. Examples are drawn mainly from developing countries.

Morbidity among bathers exposed to polluted seawater. A prospective epidemiological study.

As the first phase of a major programme to develop epidemiologically derived recreational water quality criteria for South Africa, a preliminary epidemiological-microbiological study was conducted in Cape Town during February and March 1990. Serial trials were carried out at a clean and at a relatively polluted beach over weekends. Participants were recruited at the beach, at which time information on swimming status and sociodemography was obtained. This provided for a beach-going but non-swimming control group. Symptoms which developed subsequent to the beach visit were obtained by follow-up telephone interviews conducted 3-4 days later. Water samples collected on trial days both before and during maximum swimming activity, were analysed for enterococci, faecal coliforms, staphylococci, coliphages and F-male-specific bacteriophages. Significant differences in the indicator levels at the beaches were observed. An excess in gastro-intestinal, respiratory and skin symptoms were found among swimmers relative to non-swimmers at the polluted beach. Although not statistically significant, the results are suggestive of a relationship between swimming-associated illness and water quality. The study demonstrated the feasibility of the methodology and the results of the overall programme will form the basis for the development of epidemiologically derived recreational water quality criteria for South African beaches.

Environmental health risks of toxic waste site exposures--an epidemiological perspective.

A general account is given of the problems of assessing the impact of human exposure to toxic waste sites, including the identification of truly exposed populations and of exposure pathways. Epidemiological studies of populations at risk are briefly reviewed and methodological problems summarised. These include the use of relatively weak study designs, inadequate exposure assessment and recall biases associated with symptom reporting among anxious residents living in the vicinity of waste sites. In South Africa, health risks associated with exposure to toxic waste sites need to be viewed in the context of current community health concerns, competing causes of disease and ill-health, and the relative lack of knowledge about environmental contamination and associated health effects. A nonspecific deterioration of health and well-being is more likely to result from waste site exposures than is overt clinical disease. Socially acceptable policies and controls may have to be based on criteria other than demonstrable ill-health. Detailed inventories and registries of the nature of disposed materials need to be maintained, sites of poorly controlled disposal in the past identified and selective environmental monitoring conducted. Epidemiological studies may be justified in situations where exposures well in excess of acceptable norms are demonstrated. An integrated national waste management policy for the country is urgently needed.

Occupational and environmental epidemiology--similarities and contrasts.

There has been considerable growth in the disciplines of occupational and environmental epidemiology in recent years, with both fields having to deal with increasingly complex exposure profiles and adverse health outcomes. Environmental and occupational epidemiology as distinct from general epidemiology are compared and contrasted. Similarities and differences between the two fields are systematically discussed in terms of epidemiological peculiarities, study design characteristics, sampling procedures, exposure assessment, typical biases, problems in determining causation, ethical constraints, and implementation possibilities for research findings. There is a need in South Africa to provide adequate training to health professionals working in these fields, so that high-quality research, which has the potential to contribute significantly to improvements in the health of workers and the general public, can be undertaken.

Availability of environmental health services among blacks in urban and peri-urban areas of South Africa.

Fundamental to primary health care is the need to provide adequate environmental health services to the population. Such services constitute primary prevention, and, under some circumstances, may have a greater impact on health than the provision of personal health services. This study aimed to assess the availability of environmental health services among blacks living in urban and peri-urban areas of South Africa. A stratified random sample of 800 households was selected. After discussions with the Urban Foundation, it was felt that the proportion of informal dwellings obtained (20%) underestimated the true figure, which was closer to 50%. For that reason estimates are presented for a range of values (20-50% informal dwellings). For environmental health services the percentage availability was 30-45% for reticulated water in the home; 18-29% for an inside flush toilet; and 48-62% for possession of a personal refuse receptacle. Data obtained on domestic fuel use indicated that 41-61% of households had electricity. General indicators of social class showed that 62% of households had a monthly income less than R400, and that 22-30% of mothers with children under 5 years of age had an educational level of less than Standard 5. All of the measures were substantially worse among people living in informal dwellings. The data indicate that urgent attention should be given to improving the foundations of primary health care, particularly by providing and giving attention to equity, intersectoral co-ordination and community participation in the provision of essential environmental health services.

Acute respiratory infections as an important cause of childhood deaths in South Africa.

Compared with other major preventable childhood diseases, such as diarrhoea, acute respiratory infections (ARI) have received comparatively little attention as an important cause of death in children. In this study of mortality from ARI in South Africa, national data was examined for the period 1968-1985, and data for Greater Cape Town for 1987. Almost 90% of ARI deaths were attributable to pneumonia and large inter-group differences were found that favoured whites and Asians over blacks and coloureds. For example, during 1980-1985 the mortality rate for pneumonia in coloured infants under 1 year of age was 11 times that observed in whites (88 v. 981/100,000). Pneumonia accounted for 14.5% of coloured and 12.7% of black deaths under 1 year of age during this period, compared with 6.7% of white and Asian deaths. The mortality rates from pneumonia declined substantially (50%) over the 18-year period in whites, coloureds and Asians. Sequential data for blacks is not available. There was a marked seasonality of deaths among coloured and Asian infants, with rates peaking in winter months. In Cape Town, pneumonia is now a more important cause of death among white and coloured children than diarrhoea, while it ranks with diarrhoea as a cause of death in black children. In all population groups, death rates from ARI are from 7 times to 270 times greater than those recorded in Western European countries. Studies are urgently required to discover why South African children suffer such a high mortality from ARI and how these deaths can be prevented.

Factors associated with elevated blood lead levels in inner city Cape Town children.

A cross-sectional analytical study was carried out to determine risk factors for childhood lead exposure. Blood lead levels of inner-city Sub A coloured children living in Woodstock were examined in relation to information obtained by questionnaire on environmental and social factors. The mean blood lead concentration of the population was 18 micrograms/dl. Thirteen per cent of children had blood lead levels greater than or equal to 25 micrograms/dl, the present USA 'action' level. Dusty homes and homes in a poor state of repair, over-crowding, low parental education and income, and other aspects related to family structure and socio-economic status, were associated with raised blood lead levels. It is suggested that social factors assume importance in predisposing children to lead in the environment. In particular, the over-crowded nature of the homes could have a direct bearing on the quality of the care-giving environment, providing opportunity for children's activities to go unsupervised. This could lead young children to be more exposed to accessible sources of lead associated with poor housing conditions. More attention needs to be given to examining the interaction of social and environmental factors in studies of childhood lead exposure.