Toxicity Assessment

The introduction :

Toxicology :

The goal of toxicity assessment is to identify adverse effects of a substance. depend on two factors:

i) routes of exposure ii) dose

Factors that influence chemical toxicity:

1. Dosage :

We studied chronic exposure and chronic exposure. 2. Route of exposure : Ingestion, inhalation, dermal and injection

3. age, Sex, Health, Environmental factors and Individual characteristics

Heavy metals :

It refers to any metallic chemical element which has a high density and poisonous at high concentrations. Such as mercury, cadmium, arsenic, chromium, thallium, and lead. Heavy metals cannot be degraded to a small extent they enter our bodies via food, drinking water and air. Some heavy metals like copper, selenium and zinc are essential to maintain the metabolism of the human body but at higher

Source of txicity :in children toy’s,lead dust and paintings.

Source of toxicity of heavy metals

Source of toxicity of lead:

It usually occurs over a period of months or years .

1- Lead Dust

Parents may worry about eating big chips of lead paint. When dust find in paintings of lead and children put their hands on dust and then put their hands in their mouth the toxicity happens by ingestion.

2- Lead and Home Renovations

It happen when you start a repair, painting, or renovation project in an older home, you can expose lead paint and send particles of it into the air. And when we smell these particles the toxicity occurs so it occurs by inhalation.

3- Lead in Children's Toys

The lead can be both in the paint and in the plastic itself. Sucking or chewing on the toy or getting lead on the hands and put their hands in their mouth the toxicity occur so it occur by ingestion

Source of toxicity of arsenic:

1- Drinking water

An occupational exposure because of its high toxicity

2-