Announcements 11/30/10 EXAM 3 during finals –12:15 Lecture: Sun. Dec. 12, 3:15 pm –1:40 Lecture: Mon. Dec. 13, 1 pm Final project paper – all questions answered except #14 – bring written copy to lab on Wed. or Fri., hand it in electronically with #14 by midnight that day Extra Credit: Forum on “The Human Environment at FPU”, Wed. Dec. 1, 6:30-8 pm in Monadnock Lounge of Campus Center

Environmental Health & Toxicology The main questions: How should you decide when to avoid a potentially harmful substance? How should society decide when to ban a potentially harmful substance?

What do we need to know? What do we need to know in order to decide what to do?

What do we need to know? 1.Type of harmful substance 2.Type of effects 3.Amount that is harmful 4.Amount that we are likely to get exposed to 5.Who is likely to be hurt 6.Potential benefits of the substances 7.Weigh the costs (harm) and benefits to decide what to do = “Risk management”

I.Creating Env. Health II.Principles of toxicology III.Decision-making and risk management

Environmental health focuses on… 1.Sustainable resource production 2.Air, soil and water that is free of toxics 3.Disease-causing factors in the natural, social and technological world 4.Genetically based cancers

Bird flu is an example of… 1.A global pandemic 2.An ecological disease 3.A mutualistic resource breakdown 4.A disease that only kills birds

I. Creating Env. Health Environmental health = Resource-related factors that affect human health – air, water, food, safety, etc. Env. hazards cause 25% of world’s health problems Ecological diseases affect humans and wildlife

World Health Organization measures Global Disease Burden ental_health/en/index.html “Worldwide, 13 million deaths could be prevented every year by making our environments healthier.”

Which are related to resource quality?

Global disease burden is measured by… 1.Premature deaths and disability due to disease 2.Death rates due to disease 3.Nonfatal disease outcomes

Env. health and sustainability Sustainability=? Condition in which resources are maintained so that the next generation can have the same standard of living Poor env. Health=low standard of living - indicates resources not being maintained

II. Principles of Toxicology A.There are different types of env. risks (chemical, biological, physical) B. Different substances had different effects (asphyxiant, allergen, neurotoxin,mutagen, carcinogen, teratogen) C. Toxicity is affected by many factors (stability, movement, biomagnification, amount/dose, duration of exposure, type of organism, etc.) D. Identifying effects is difficult E. We use Risk management to Weigh costs and benefits, minimize risks

II. Principles of Toxicology A.Types of env. risks 1)Chemical: solid, liquid, gas Toxic = harmful in small doses 2)Biological: Infectious agents (living organisms that cause harm) 3)Physical: Fire, radiation Hazardous=dangerous – explosive, etc. – but need large amounts (toxins are hazardous but not all hazards are toxic!)

Microwaves used in cell phones are an example of which type of risk? 1.Chemical 2.Physical 3.Biological

B. Different toxic substances have different effects on living creatures. 1)Asphyxiant: restricts oxygen intake (ex.: Carbon monoxide) 2)Allergen: Causes allergic reaction (ex.: pollen) 3)Neurotoxin: Damages nerve cells (ex.: lead) Neurotoxins can bind to different parts of a nerve cell, prevent it from sending/receiving signals properly

4)Mutagen: Causes DNA mutation (ex.: radiation, benzene) – may or may not cause cancer 5)Teratogen: Causes birth defect in developing fetus (ex.: Mercury, pesticides, many drugs)

6)Carcinogen: Causes cancer (ex.: benzopyrene in cigarrettes) 7)endocrine disruptor: Alters hormone system (ex.: some pesticides, plastics) some substances can have more than one effect – e.g. organochlorines – group of pesticides Research in Mexico suggests dramatic impacts of agricultural pesticide exposure on neurological development in children.

A substance that causes a birth defect is called a… 1.Carcinogen 2.Teratogen 3.Mutagen 4.Fetal toxin

III. Principles of Toxicology 1) Stability/persistence (resistance to decomposition) Many chemicals break down in sunlight and/or oxygen More resistant = more persistent! Lasts longer C. Toxicity of a substance depends on several factors

2) How substance moves: Does it need a “Vehicle” such as solvent (water, oil, gas) to carry it; does it move in air, etc. Solvent - A Chemical (Toluene) solvent used to thin two part epoxy m/English/R/R-1Solvents.html

3) Does substance Bioaccumulate = build up in the body of an individual or Biomagnify= build up through the food chain?

Biomagnification =Amount of substance increases in each higher level of food chain 1.Water - small amount  2.Phytoplankton (=tiny floating plants)  3.Zooplankton (=tiny floating animals)  4.Small fish  5.Larger fish, birds, frogs  6.Top predators: largest amount

Every time we eat food with certain pesticides, some of the pesticide stays in our body. This is called 1.Disgusting 2.Carcinogenic 3.Bioaccumulation 4.Biogenic 5.Biomagnification

A substance found at higher amounts in organisms higher in the food chain has 1.biomagnified 2.bioaccumulated 3.ecotoxified 4.ecovillified 5.re-gifted