Understanding environmental science and human health impacts requires examining multiple interconnected systems and pathways.
Environmental Science A Level topics cover crucial concepts like biogeochemical cycles and pollution pathways. These systems show how contaminants move through air, water, and soil, affecting ecosystems and human health. Critical pathway analysis helps assess pollution risks by tracking contaminants from their source through environmental media to potential receptors. This source-pathway-receptor model is especially important in contaminated land risk assessment and groundwater protection.
The health impacts of environmental pollutants are clearly demonstrated through the effects of smoking on respiratory health. When cigarette smoke enters the respiratory system, it damages the protective mechanisms of the airways and destroys delicate alveoli in the lungs. This leads to serious respiratory diseases including chronic bronchitis, emphysema, and lung cancer. Long-term exposure causes progressive deterioration, with smokers' lungs showing significant damage after 10 years of use. The source-pathway-receptor concept applies here too - cigarette smoke (source) travels through the respiratory tract (pathway) to affect lung tissue (receptor). Understanding these relationships helps assess both environmental and health risks. For people with asthma, exposure to cigarette smoke can trigger severe reactions by irritating already sensitive airways and increasing inflammation. The destruction of alveoli, characteristic of emphysema, reduces the lung's ability to exchange oxygen and carbon dioxide effectively. This demonstrates how environmental exposures can permanently alter biological systems and human health outcomes.
These interconnected concepts form the foundation for understanding environmental impacts on human and ecosystem health. Whether examining large-scale pollution or individual exposure pathways, the principles of transport, exposure, and effect remain consistent across different scenarios and scales.