Nano-silver which is widely used is reported to be toxic to beneficial bacteria that break down wastes and recycle nutrients in the soil. Fullerenes, which are used in electronics, electro-optics, cosmetics and cancer therapy, cause oxidative brain damage (through lipid peroxidation) in juvenile largemouth bass via the olfactory nerve. Carbon nanotubes cause inflammation and granulomas in the lungs of mice even at the lowest concentration when aerosols of multiwall carbon nanotubes were made to be inhaled.
Quantum dots which are nanosized semi-conductors that generate electron-hole pairs confined in all three dimensions (quantum confinement) behave like giant molecules rather than bulk semiconductors. Quantum dots are widely used in light emitting diodes, transistors, solar cells, drug delivery, cancer therapy and cell imaging. But most quantum dots contain highly toxic metals such as cadmium, which tends to be released when they enter the cells or organisms. Many kinds of nanoparticles enhance the formation of insoluble fibrous protein aggregates (amyloids), which are associated with human diseases including Alzheimer’s, Parkinson’s and Creutzfeld-Jacob disease.

It is possible that nanoparticles may be inhaled, ingested or taken in through contact of nano products with the skin. Through inhalation of nanoparticles the possible diseases include asthma, bronchitis, emphysema, lung cancer and neurodegenerative diseases. Nanoparticles in the gastrointestinal tract have been linked to Crohn’s disease and colon cancer. Nanoparticles that enter the circulatory system can cause arteriosclerosis, blood clots, arrhythmia, heart diseases, and ultimately death from heart disease. Nanoparticles entering other organs, such as liver, spleen, etc., may lead to diseases of these organs. Some nanoparticles are associated with autoimmune diseases, such as systemic lupus erythematosus, scleroderma, and rheumatoid arthritis.

Action needed
Obviously not all nanoparticles are harmful, but exhaustive tests are needed to ascertain the ill effects of the engineered nanoparticles. It is clear from the above evidence that an urgent action research is needed not only to stem but also to reverse the unregulated tide of nanoparticles that are released into the market.
The above existing evidences require the following actions.
- Nano-ingredients in food, cosmetics and baby products such as silver, titanium oxide, fullerenes etc., for which toxicity data already exist should not be allowed to be used.
- Nano-products should not be commercialized until they are demonstrated safe and obey regulations.
- Consumer products containing nanotechnology should be clearly labeled about the amount of nanomaterial content.
- Manufacturers of nano-products should properly register their products to the appropriate authorities and make it public without keeping secret.
- Nanotechnology research activities must be made comprehensible to the public performed in a transparent manner, accountable, safe and sustainable, and not pose a threat to the environment.
- Intensive research into the hazards of nanotechnology should also be carried out in equal proportion to the new commodity development.