Agriculture and culture read about how the spread

Agriculture and culture: read about how the spread of crops and livestock started and drove the course of civilization http: //www. pbs. org/gunsgermssteel/

U. S. Department of Agriculture Food Guide Pyramid; http: //www. mypyramid. gov/index. html North Americans consume on average about 35% of their daily calories as fat.

• Distinguishes between healthy and unhealthy types of fat and carbohydrates. • Fruits, vegetables, healthy fats and whole grain foods are encouraged. • Consumption of refined carbohydrates, butter and red meat should be limited. Source: Scientific American 2002

Causes of Famine and Hunger Hotspots • Civil Wars • Drought • Government Incompetence

Pest Any organism (plant, animal, microbe, fungus) that has a negative effect on human health or economics

The Early Years Of Chemical Pest Control • First-generation pesticides (inorganic) – First attempt at chemical technology – Included heavy metals such as arsenic and lead – Toxic to humans and agricultural plants – Pests developed resistance

Chemical Technology “Improvements” • Second-generation pesticides – Used after WWII – Organic chemical – Toxic to humans and agricultural plants – Pests developed resistance

DDT: the magic bullet –Cheap –Broad-spectrum and persistent –Effective for disease prevention (typhus fever, malaria) –Expanded agricultural production –Paul Muller awarded Nobel prize in 1948 –Kills birds, lead to Silent Spring by Rachel Carson –Banned in U. S.

Ethics of DDT Cheap & effective control of malaria (lethal disease found in tropics). Other means of prevention include mosquito netting and window screens (more expensive) Should people have access to DDT to treat their homes?

Pesticide Use in the United States

Chemical Technology Problems • Development of resistance by pests • Resurgences and secondary pest outbreaks • Adverse environmental and health effects

pesticide treatment

pesticide treatment

History of Pesticide Resistance

Chemical Technology Problems • Resurgences: after “eliminating” a pest, its population rebounds in even higher numbers than previous levels. • Secondary outbreaks: outbreaks of species’ populations that were not previously at pest levels.

Some Examples of Insect Food Chains

Human Health Effects • Cancer, dermatitis, neurological disorder, birth defects, sterility, endocrine system disruption, immune system depression • Agricultural workers suffer acute poisoning during pesticide application • Aerial spraying and dumping bring pesticides in contact with families and children

Bioaccumulation Biomagnification

Natural Pest Control • Cultural control (hygiene) • Control by natural enemies – Introduce or encourage predators of the pest • Genetic control • Natural chemical control

Genetic Control • Plants or animals are bred to be resistant to the attack of pests • Introduction of genes into crops from other species: transgenic crops • Sterile males are released into pest population

Natural Chemical Control • Manipulation of pests’ hormones or pheromones to disrupt the life cycle. • Japanese beetle trap.

Integrated Pest Management IPM • An approach to controlling pest populations using all suitable methods chemical and ecological - in a way that brings about long-term management of pest populations and also has minimal environmental impact

When is certified organic food worth your money?