Biological Effects Of Carbon Nano Material On Respiratory System

Atmospheric pollution is aggravated worldwidely in recent years, particularly in many areas of china.PM2.5(ultrafine particles) contained in polluting gases plays a decisive role for the air quality, which hasgotten people’s attention. Relevant data shows that PM2.5is carcinogenic and carbonaceous compositionoccupies the main proportion about40%in PM2.5, so it is important to study the biosecurity ofcarbon-based materials.Research of the topic aims at three kinds of carbon nano materials, including the graphene (flakestructure, d<500nm), single-walled carbon nanotubes (10to100μm in length), multi-walled carbonnanotubes (10to100μm in length). Carbon nano materials were absorbed by lung tissue of the SD malerats by intubation. The experiment explores the damage effects of three kinds of carbon nano materialsthrough respiratory system on the target tissues include lung tissue, liver tissue and brain tissue usingtransmission electron microscope, optical microscopy, synchrotron radiation technique and molecularbiology detection technique. The main research results are as follows:On one side, each low concentration group of grapheme, single-walled carbon nanotubes andmulti-walled carbon nanotubes has not obvious damage effect on the tissue of rat, but each highconcentration group of them has obvious damage effect, and the damage effect present positive correlationwith the increase of concentration of carbon nano materials. Morphological damage in rat tissues increasedwith increasing concentration, we found the deposition of nano particles in the lung tissue, decreases ofsome trace elements in brain tissues of rats.On the other side, damage degree of carbon nano materials on lung tissue, liver tissue, brain tissue ofrats showed a trend of gradually decreasing, which is related to that the experiment take the lung tissue ofrats as the direct object exposure and the liver tissue and brain tissue have the different physical locationfrom lung tissue.