Air Pollution
Air pollution is the transfer of harmful amounts of natural and synthetic materials into the atmosphere as a direct or indirect action of human activity. Air pollution can be divided into mobile and stationary sources. Mobile sources include various modes of transportation such as automobiles, busses, trains and aeroplanes whereas stationary sources include factories, incinerators and electric power plants. (Fuggle R.F., Rabie M.A. 1992 : 601) Air pollution in Greater Johannesburg constitutes a number of driving forces from human activities

 Air pollution in Greater Johannesburg differs according to area with the worse affected areas being Informal Settlements. Air pollution are furthermore being monitored according to guidelines

Air quality is affected by economic activities which introduces pollutants into the atmosphere that pose threats to human health and other life forms on earth. It furthermore has the potential to change the climate with unpredictable, but potentially severe consequences on a local and global scale. Because large bodies of air cannot be contained, atmospheric pollution can only be controlled at its source.

Major areas of concern are high levels of smoke and other pollutants in poorer urban and rural households without electricity, and the impacts of the mining, energy, mineral and petro-chemical industries on air quality standards (Environmental Management Policy for South Africa, 1998).

WATER POLLUTION

The dense population, along with the growing industry, impacts negatively on the quality of the water, and consequently, the Jukskei is probably one of the worst preserved rivers in South Africa (Eastern Metropolitan Local Council, 1997).

Possibly the most serious related water problem identified and quantified is that of blocked and leaked sewers in Soweto and some parts of the Johannesburg CBD

Underground water, like surface water, can be polluted from a number of sources:

In addition to water scarcity, a large percentage of drinking water is lost due to degradation of water supply infrastructure and leakage overview of DPSIR in water pollution chapter. The upper Klip River in the south is located in an area of urban development and mining land, and is subjected to intense pressure from human activities.

Other than the Klip River, the Southern Metropolitan Local Area does not have access to any major potable water resource. The communities, which are exposed to raw sewage and polluted streams and rivers, face serious health hazards (Southern Metropolitan Local Council, Environmental Management Fact-Pack, 1997).

The Jukskei River Catchment in the north is one of the main tributaries of the Crocodile River, upstream of the Hartebeespoort Dam. The Catchment area drains a large proportion of the Witwatersrand. The source of the Jukskei River is located within the Eastern Metropolitan Sub-structure. In 1991, the population of this Catchment amounted to 790 000. 

The main water feature in the Southern Metropolitan Local Council is the Klip River, which eventually drains into the Vaal River. However the main concerns from an environmental perspective are the impacts of the increasing demands on potential resources and the impact of pollution on downstream impoundment and users of this water source.

The water quality of rivers in Greater Soweto (Southern Metropolitan Local Council) shows evidence of mining pollution:

• low pH values,
• high electrical conductivity,
• high sulphate values; and
• contamination from raw sewage (as a result of sewer blockages which occur from time to time).

Surface water running through the Eastern Metropolitan Local Council, especially in the vicinity of Alexandra, shows evidence of sewage pollution:

• high E.coli (an indicator organism for faecal contamination)

  • low pH values (indicating acidity or alkalinity)
  • high electrical conductivity
  • varied ammonia and COD levels and

LAND POLLUTION
Overcrowding in Greater Johannesburg causes exploitation of the land beyond its capacity, which leads to land pollution. This exceeds the capacity of sewer systems and landfill sites. Sewage problems mainly exist in large parts of Alexandra and Soweto townships. To the south and southwest of Johannesburg, dust pollution from mine dumps are the main sources of environmental degradation, whilst the CBD experiences continuous overflowing of sewers, especially in Hillbrow, Newtown and Jeppestown. All these activities reduce the quality of the surface environment. The main sources of land pollution were identified as informal settlements, waste disposal sites, mining activities and activities in CBD’s.

NOISE POLLUTION
Noise is becoming an important concern for communities in the Greater Johannesburg area due to its great degree of urbanity. Environmental noise is specified in relevant by-laws or regulations in terms of the ambient sound levels for the area under consideration. The sound levels are determined by existing land uses, traffic densities and other factors, such as the time of the day. Complaints about loud noise are usually from nightclubs, road compressors. Industrial sources and sewage works, religious ceremonies and vehicular traffic.

UNHEALTHY HOME ENVIRONMENTS
To assess the state of the housing conditions within Greater Johannesburg it will be necessary to look at :Housing provision.  The demand for housing is increasing, but much of it takes the form of meeting the needs of people who cannot afford and do not want to spend much on housing (as they send money home). Most people do not qualify for subsidies (illegal immigrants or legal migrant from outside South Africa) or do not want to take up their subsidy in Johannesburg as they intend to settle elsewhere (labour migrants).