Download Harmful Chemicals - Science With Horne

Harmful Chemicals
* neurotoxin
* young children
and fetuses
are the most
vulnerable
Sources of Lead Exposure
ammunition
picture tube
pipes & solder
ceramic glaze
Reducing Lead Exposure
* neurotoxin
* young children
and fetuses
are the most
vulnerable
Sources of mercury in the environment
elemental (Hg) and inorganic (Hg2+)
NATURAL
weathering
ANTHROPOGENIC
waste incineration
How mercury enters humans
* inhalation (elemental & inorganic)
* Eating fish contaminated with methyl mercury (CH3Hg)
Once inorganic mercury falls into
the water, bacteria convert it to an
organic form, methyl mercury.
This is easily biomagnified because
of its solubility in fats (lipids).
** Acid deposition can accelerate conversion to methyl mercury **
Reducing Mercury Exposure
* Toxic & persistent
* Can cause respiratory
problems
* Organochlorines may
act as endocrine
disrupters
Uses of Chlorine
TCE
chlorinated
solvents
disinfectant in water treatment
production
of PVC
Reducing use of Chlorine
use O3 or H2O2 to
“bleach” pulp/paper
alternatives to chlorine
based cleaners
use O3 to disinfect
drinking water
use plant based plastics
instead of PVC plastic
* Chlorinated
hydrocarbon
compounds
* Some are
carcinogenic
* Endocrine,
reproductive, and
immune disruptors
Where do dioxins come from?
* Unwanted by-products of
industrial processes that use
chlorine
production
of PVC
* Incineration of municipal & medical waste
Most human exposure comes from . . .
FOOD
most notably contaminated fatty
meats & dairy products
POPs Treaty
persistent organic
pollutants
* 2001 international treaty
* “Dirty Dozen” pollutants including DDT,
PCBs, and dioxins
* GOALS  1> ban/phase out use of dirty dozen
2> detoxify/stockpile dirty dozen
* The United States still has not ratified the treaty
Banned/highly
restricted chemicals
▪



▪
Pesticides
Insecticides
Industrial Waste
Stockholm Convention
on Persistent Organic
Pollutants
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Aldrin
Chlordan
DDT
Dieldrin
Endrin
Heptachlor
Hexachlorobenzene
Mirex
Toxaphene
PCBs
Polychlorinated Dioxins
Polychlorinated Furans