Biophysical Hazards Reading Smith Ch 10 Biophysical Hazards

Biophysical Hazards

Reading • Smith Ch 10

Biophysical Hazards • “dustbin” category for various assorted hazards – disease – extremes of temperature – wildfire

Disease organisms • • Microbes: Bacteria, viruses, prions Parasites can affect people directly can affect crops

Infectious Disease • Interaction between – population of disease organism – population of host organism – often complex transgenic relationships

• Lyme disease

Infectious Disease • Endemic: always present • Epidemic: periodically active – Major Epidemics: Pandemics

Infectious Disease • Epidemic/endemic depends on size of host population – Too small: tendency toward epidemics – Large enough: tends to be endemic

Flu in Manitoba

Infectious Disease • Tendency for ecological balance between disease organisms and their hosts • Very deadly diseases – kill their hosts too quickly to spread efficiently – but modern communications can change that …

• Fighting flu in Hong Kong

Anthropological speculation • Humans evolved in Africa • Human population designed to be naturally regulated by the diseases of Africa • Take humans out of Africa: – Epidemic growth of human population • Humans as an epidemic?

Black Death Pandemic 1347 -1350 • Bubonic plague • Killed 50 million Europeans in 3 years – 1/3 of European population • Severe social disruption – Weakened the feudal system

Black Death Pandemic 1347 -1350 • Losses of urban populations: – London: 50% loss – Beijing: 40% loss

Black Death Pandemic 1347 -1350 • Western Europe in population crisis by 1347 – war, famine, disease, harvest failure – soil exhaustion • Black Death the latest of a series of calamities • Population took until 1600 s to rebuild

1918 -19 Influenza Pandemic • WW 1: killed 9 million in 4 years • Influenza: killed 25 -37 million in 2 years – 16 million killed in India

Sydney NSW

• Ann Arbor MI Fall 1918

• High River Alberta, Fall 1918

• Potential public enemy #1

Plague in the USA • San Francisco 1909 • New Orleans 1914 • Now endemic in California – transgenic shift from rats to ground squirrels

Bubonic Plague in CA

Promoting/Discouraging Disease • Increase probability of infection – population builds resistance – example of Tuberculosis in Victorian England • Decrease probability of infection – population does not get the exposure to build resistance – example of Polio

Polio in LA, 1950 s

Biological limits • People suffer irreversible deterioration and death if internal body temperature – falls below 26 degrees C – rises above 40 degrees C

Extreme Cold • Windchill, hypothermia – severe high-latitude/high-altitude weather conditions – cold water exposure

Extreme temperatures • Cold weather kills fewer than hot weather – easier to keep warm than keep cool – body designed to survive cooling better than overheating

The Humidex Chart

• US OSHA heat chart

Extreme temperatures • Dec 1983 cold snap kills 150 in USA • 1979 -80 5000 heat deaths in USA • 1936 -75 20, 000 died in USA from heat & humidity

Extreme temperatures • Kills the elderly, those with compromised circulatory & respiratory systems • Urban areas worse: heat island effect, worse in inner city • Set to worsen with global warming

Extreme temperatures • 1955 heat-wave in LA killed 946 people – twice as deadly as 1906 San Francisco earthquake

• Toronto Telegram June 1959

Frost Hazards • Bad for agriculture, especially tender crops close to harvest time • Various devices to reduce frost risk • Locate farms to avoid frost

The Niagara Fruit Belt • Mainly on the Lake Ontario plain, N of the Escarpment • Cooler temperatures here retard fruit growth, reducing risk of a spring frost • Or make ice wine

Wildfire Hazards • Promoted when fuel accumulates (dry vegetation) and meets dry, windy, warm weather

October 1871 USA • Wildfire in Michigan & Wisconsin • Follows 14 week drought • Land-clearance fires whipped up by strong winds • Burns 1. 7 M hectares • Kills 1500 • World’s greatest wildfire disaster?

Ash Wednesday 1983 • • Victoria & South Australia 1983 El Nino drought & heatwave Strong winds (70 km/h+) Killed 76, 8000 homeless

• Ash Wednesday fires 1983 NSW • 6 firefighters died here

Macedon NSW

Brushfires, 1983 drought Australia

1983 El Nino drought fires, Australia

NSW Fires Dec 1993 -Jan 1994 • 1992 -3 El Nino • Affected 1 M Hectares • 300+ fires along 1100 km coastline fanned by strong winds • Destroyed 200 buildings • Killed 4

Jan 1994 NSW

• Jan 1994

Australian Fires • Burn faster than other people’s fires – 800 Hectares/hour in Australia – 1 Hectare/hour in Northern USA

Dandenong NSW 1997

• Engadin NSW 1997 controlled burn

Engadin NSW 1997

Pillaga NSW 1997

Lithgow NSW Dec 1997

• Lost home, Sydney NSW Dec 1997

Heathcote NSW Dec 1997

• Mt Martha NSW Jan 1998

Icon in the smoke, Jan 1998

Smoky Sydney Dec 1997

Sussex Inlet NSW Jan ‘ 02

Toomerong NSW Xmas 2001

Causes of “Wildfires” • Lightning strikes • Human carelessness – rubbish that burning gets out of control – car exhausts, discarded glass containers etc. , • Fires maliciously set • Effects of urban growth

Fuel Issues • Fire is part of the natural ecology • Controls fuel accumulation • Requires fuel accumulation – tends to be seasonal – Toronto area: • first warm weekend (usually April)

New Jersey

New Jersey brushfire

Northern Quebec

Effects of Fire Prevention • May cause fuel to accumulate to dangerous levels • Pre-emptive burns, controlled burns required

Some areas fire-prone • Malibu California – Seasonally-dry Chaparral vegetation which burns hot and fast – Seasonally strong Santa Ana winds can whip up fires into a conflagration – Inhabited by the rich, dislike restrictions on their lifestyle – Demand good fire protection