Assistant Lecturer- Zoology Department Faculty of Science Effect of Nanoparticle treatment on trihalomethane toxicity induced on experimental animals Presented by Heba Nageh Gad EL-Hak Assistant Lecturer- Zoology Department Faculty of Science

What are the trihalomethane? Trihalomethanes (THMs) are chemical compounds in which three of the four hydrogen atoms of methane (CH4) are replaced by halogen atoms. Many trihalomethanes uses in industry as solvents or refrigerants. THMs are also environmental pollutants, and many are considered carcinogenic.

How it is formed? Trihalomethanes are formed from the reaction of chlorine or bromine which is used to disinfect water for drinking with organic matter present in the water being treated.

formed in swimming pools which are disinfected with chlorine or hypochlorite in the haloform reaction with organic substances (e.g. urine, sweat, hair and skin particles). Some of the THMs are quite volatile and may easily vaporize into the air. This makes it possible to inhale THMs while showering, for example. The EPA, however, has determined that this exposure is minimal compared to that from consumption. In swimmers, uptake of THMs is greatest via the skin with dermal absorption accounting for 80% of THM uptake. Exercising in a chlorinated pool increases the toxicity of a "safe" chlorinated pool atmosphere[with toxic effects of chlorine byproducts.

What are Nanoparticles? A nanoparticle is a small object that behaves as a whole unit in terms of its transport and properties. Nanotechnology is an emerging and fast-growing technology. Currently, there are thousand of nanotechnology-based products on the market. There are several chemical methods to synthesize nanoparticles of gold, silver, and iron oxide, as co- precipitation or thermal decomposition. But physical methods either are not widely known or publicized. There is the laser ablation in a liquid medium, which can obtain any type of nanoparticles, but lasers for this technique are expensive.

In the area of water purification, nanotechnology offers the possibility of an efficient removal of pollutants and germs. Today nanoparticles, nanomembrane and nanopowder used for detection and removal of chemical and biological substances include metals (e.g. Cadmium, copper, lead, mercury, nickel, zinc), nutrients (e.g. Phosphate, ammonia, nitrate and nitrite), cyanide, organics, algae (e.g. cyanobacterial toxins) viruses, bacteria, parasites and antibiotics. Basically four classes of nanoscale materials that are being evaluated as functional materials for water purification e.g. metal- containing nanoparticles, carbonaceous nanomaterials, zeolites and dendrimers. Carbon nanotubes and nanofibers also show some positive result.

Nanomaterials reveal good result than other techniques used in water treatment because of its high surface area (surface/volume ratio). It is suggested that these may be used in future at large scale water purification.

Nanoparticle Applications in Medicine The surface change of protein filled nanoparticles has been shown to affect the ability of the nanoparticle to stimulate immune responses. Researchers at Rice University have demonstrated that cerium oxide nanoparticles act as an antioxidant to remove oxygen free radicals that are present in a patient's bloodstream following a traumatic injury. The nanoparticles absorb the oxygen free radicals and then release the oxygen in a less dangerous state, freeing up the nanoparticle to absorb more free radicals.

The present study is carried out to investigate the possible protective role of nanoparticle in decrease the toxicity induced by the trihalomethane on experimental animal.