Today I’m going to talk about: Hazardous wastes

I’ve divided my presentation into two parts:

First I’d like to introduce the wastes and second I’ll present sources

of hazardous wastes.

So, let’s start with introduce

Hazardous Wastes, solid, liquid, or gas wastes that can cause death,

illness, or injury to people or destruction of the environment if

improperly treated, stored, transported, or discarded. Substances are

considered hazardous wastes if they are ignitable, corrosive, reactive, or

toxic. Mixtures, residues, or materials containing hazardous wastes are

also considered hhazardous wastes.

Many dangerous substances can be used only with special precautions

that decrease their risks. When discarded, these substances are no longer

under the direct control of the user and may pose special hazards to people

or other organisms that come in contact with them. Because of such

potential risks, hazardous wastes are processed separately from ordinary

wastes.

There are foor sources of hazardous wastes: Industrial, Agricultural,

Household and Medical.

A Industrial Wastes

Hazardous wastes are generated by nearly every industry; those

industries that themselves generate ffew hazardous wastes nonetheless use

products from hazardous waste generating industries. Other hazardous wastes

are generated in the manufacture of fiber optics and copper wire used in

electronic transmission, as well as magnetic disks, paper for technical

manuals, photographs for packaging and publicity, and trucks for

transportation of the finished product.

B Agricultural Wastes

Industry is not alone in generating hazardous wastes. Agriculture

produces such wastes as pesticides and herbicides and the materials used in

their application. Fluoride wastes are by-products of phosphate fertilizer

production. Even soluble nitrates from manure may dissolve into groundwater

and contaminate drinking-water wells; high levels of nitrates may cause

health problems.

C Household Wastes

Household sources of hazardous wastes include toxic paints, flammable

solvents, caustic cleaners, toxic batteries, pesticides, drugs, and mercury

from broken fever thermometers. Local waste-disposal systems may refuse

these items. If they are accepted, careful monitoring may be required to

make sure soil or groundwater is not contaminated. The householder may be

asked to recycle or dispose of these items separately.

Renovations of older homes may cause ttoxic lead paint to flake off

from walls. Insulation material on furnace pipes may contain asbestos

particles, which can break off and hang suspended in air; when inhaled,

they can cause lung disease and cancer.

D Medical Wastes

Hospitals use special care in disposing of wastes contaminated with

blood and tissue, separating these hazardous wastes from ordinary waste.

Hospitals and doctors’ offices must be especially careful with needles,

scalpels, and glassware, called “sharps.” Pharmacies discard outdated and

unused drugs; testing laboratories dispose of chemical wastes. Medicine

also makes uuse of significant amounts of radioactive isotopes for diagnosis

and treatment, and these substances must be tracked and disposed of

carefully.