9.1 Urbanization on the Natural Environments and Housing Impact on the Natural Environments

Definition of Pollution: Pollution refers to the introduction of substances into the environment that result in harmful effects on plants, animals, and humans. (Page 2)
Scope of Impact: The process of housing and urbanization affects land, water, and air quality through the production of waste and the consumption of natural resources.

Land Requirements: Urban centers and cities must be constructed on flat land. (Page 5, 6)
Deforestation: An estimated $18.7 \times 10^6$ acres of forests have been lost to clear space for the growing urban population. This process is explicitly identified as deforestation. (Page 5, 6)
Raw Materials for Furnishing: Large quantities of natural resources are used for interior components; for example, furniture in homes is typically manufactured from wood. (Page 5, 6)
Energy Production: Electricity for housing is generated by the burning of natural gas. This gas needs to be extracted directly from the natural environment. (Page 6)

Daily Consumption Volume: Large cities utilize approximately $504 \times 10^9$ liters of water per day. (Page 6)
Global Water Stress: Approximately one in four cities faces water stress. This condition is driven by two primary factors: * Geographical limitations. * Financial limitations.
Extraction and Transport: The extraction of water is not limited to the immediate surrounding areas of a city. Due to scarcity, some water is sourced and transported from as far as $30,000\,km$ away. (Page 6)

Types of Household Waste Contributing to Land Pollution: * General Garbage: This includes organic food waste. * Electronic Waste (E-waste): Specific examples include discarded batteries. (Page 3)
Impact of Landfills: When household waste is deposited into landfills, it creates environments that attract pests, specifically rodents and flies. (Page 3)

Primary Sources of Water Contaminants: * Detergents: The act of washing clothes and dishes directly at river sites releases detergents into the water bodies. (Page 3) * Human Waste: In areas such as slums, human faeces and urine are often discharged directly into nearby water bodies. (Page 3)
Environmental Degradation: Detergents decrease the overall water quality, rendering the environment toxic or harmful to aquatic living things. (Page 3)
Public Health Impacts: * Faeces and urine lead to a significant increase in bacteria within the water supply. * Drinking or using this contaminated water leads to the spread of water-borne diseases, specifically highlighting cholera and dysentery. (Page 3)
Subsurface Impact: Waste management issues can lead to the contamination of groundwater. (Page 3)

National Recycling Programme: In Singapore, public waste collectors are mandated by the National Recycling Programme to facilitate the recovery of materials. (Page 4)
Structural Features in Housing: Residential housing blocks are equipped with recycling bins (often provided by companies like Sembcorp) located under the blocks to encourage residents to divert waste from landfills. (Page 8, 9)
Recyclable Material Categories: * Paper: Includes newspapers, magazines, books, and paper packaging. (Page 8) * Plastic: Includes plastic bags, plastic containers, and bottles. (Page 8) * Glass: Includes wine bottles, beer bottles, and glass jars. (Page 8) * Metal: General metal scrap and containers. (Page 8)

Assessment of Hazards: The study of housing impact includes identifying the specific hazards presented by air pollution to human health and the environment. (Page 7)
Control Mechanisms: Strategies are required to manage and mitigate emissions stemming from the energy requirements and infrastructure of urban housing. (Page 7)