Human beings are an integral part of the environment, but their increasing population, technological development, industrialization and changing patterns of consumption have greatly altered natural ecosystems. Environmental health is closely connected with these changes because environmental degradation affects the quality of air, water, food, soil and living conditions. Human activities can create both direct and indirect environmental impacts, many of which contribute to disease, ecological imbalance and loss of natural resources. One of the major human impacts on the environment is population growth. As population increases, the demand for land, food, water, energy and housing also rises. Expansion of settlements often leads to the conversion of forests, wetlands and agricultural land into residential and commercial areas. Rapid urbanization creates pressure on sanitation, waste management, transport and water-supply systems. Poorly planned urban growth can result in overcrowding, inadequate drainage, accumulation of waste and increased exposure to environmental hazards. Deforestation is another significant impact. Forests are cleared for agriculture, mining, roads, industries, settlements and commercial activities. Deforestation destroys habitats and reduces biodiversity. It also contributes to soil erosion, changes in rainfall patterns and increased carbon dioxide concentrations. Forest destruction can affect environmental health by reducing natural protection against floods, increasing land degradation and disturbing ecological systems that help regulate infectious diseases. Industrialization has substantially changed the environment. Industries release smoke, particulate matter, toxic gases, wastewater and solid and hazardous wastes.