Summary ENHS 321

• Assesses environmental factors that influence human health and quality of life • Seeks to prevent adverse effects on human health and ecological systems • Contains environmental toxicology within its scope Environmental health hazards • Types include: • Physical hazards (floods, blizzards, landslides, radon, UV exposure) • Chemical hazards (disinfectants, pesticides) • Biological hazards (viruses, bacterial infections) • Cultural or lifestyle hazards (drinking, smoking, bad diet, crime in neighborhood) Infectious disease •In communicable or transmissable disease, a pathogen attacks a host, • either directly or through a vector (e.g., mosquito that transfers a malaria parasite to hosts) • … and the pathogen can be transmitted from one host to another. • Infectious disease causes 25% of deaths in the world and nearly half of deaths in developing nations. Many health hazards also exist indoors • Substances in plastics and consumer products • Lead in paint and pipes • Radon • Asbestos • PBDE fire retardants Toxicology - Is the study of poisonous substances and their effects on humans and other organisms • Toxicologists assess and compare toxic agents, or toxicants, for their toxicity, the degree of harm a substance can inflict. • Environmental toxicology focuses on effects of chemical poisons released into the environment. Environmental toxicology •Toxicants are studied that come from or are discharged into the environment and their: • Health effects on humans • Effects on animals • Effects on ecosystems Animals are studied: • For their own welfare • As “canaries in a coal mine” to warn of effects on humans Synthetic chemicals are everywhere in our environment • Many thousands have been produced and released. • Some persist for long time periods or travel great distances. • Of the 100,000 synthetic chemicals on the market today, very few have been thoroughly tested for harmful effects. • 2002 USGS study: 80% of U.S. streams contain up to 82 wastewater contaminants, including antibiotics, perfumes, detergents, drugs, steroids, disinfectants, and so forth. Rise of synthetic chemicals .............................CONTINUED.........................