Human Health and Environmental Hazards

1. Cultural Hazards Matter of human choice Engagement in risky behaviour leading to harm / decreased health Smoking  Lung Cancer Drug Use  nervous system damage Sunbathing  Melanoma Overeating  Heart Disease / Diabetes Risky sexual practices – STDs HIV/AIDS Living in inner cities  asthma Others?

2. Physical Hazards Natural disasters 2011 Japan earthquake and tsunami 2010 Haiti earthquake 2005 Hurricane Katrina (Louisiana) 2004 Indian Ocean tsunami Tornados, earthquakes, floods, forest fires, landslides, volcanic eruptions… Difficult / impossible to predict Choice of where to live? How does poor preparation result in natural disaster potential?

3. Biological Hazards Pathogenic bacteria, viruses, fungi, worms, protozoans Only in the 20 th century – antibiotics and immunization Despite advances, most diseases of 500 years ago are still present 25% of global deaths are due to infectious and parasitic diseases

Top 6 (mortality) Acute Respiratory Infection (e.g. pneumonia) 4 million / year Diarrheal diseases (e.g intestinal viruses) 2 million / year HIV / AIDS – 2 million / year Tuberculosis – 1.5 million / year Malaria – 1 million / year Measles – 0.5 million / year

4. Chemical Hazards Result of industrialization (many cancers have increased since the Industrial Revolution) Ex. Pesticides, cleaning agents, fuels, paints, medicines …. Exposure is via ingestion, inhalation, or dermal absorption Birth defects Infertility Brain impairment

Toxicity – causing harm – depends on A) exposure – quantity of the toxin - length of time in contact B) dose – actual absorption of the chemical by the body Sometimes there is a threshold level below which the body’s defenses can deal with the chemical. Sometimes there is no threshold (there is often debate on this point)