Nanomaterials include nanoparticles (e.g. metal oxides), nanowires, nanotubes, quantum dots and carbon fullerenes (buckyballs) etc. Thus nanomaterials are well known for their various beneficial uses in the medicines, engineering, computer etc., in spite of that it is associated with many hazards of human health. The exposure of nanomaterials through dermal contact, inhalation, ingestion, exposure to broken tissues or wounds etc. can cause adverse effects on body. This toxicity thus limits the use of nanomaterials.It is appropriate to start with a warning. In the history of technology there were two toxic substances that were cause serious deaths: quartz and asbestos. The harmfulness of inhaling fine particles of quartz’s was recognized in the eighteenth century and the effect of asbestos was recognized at the end of the nineteenth century. The physicians and scientists were try understand the mechanisms of toxicity, that was provide the support from the industries concerned, driven by the medical mindset that the curation from these was possible by found the mechanism of toxicity. The effective regulation and enforcement were not introduced that leads to the longer exposure and effect of both to the workers, and they continued to die (and still do). The warning is this: it is not necessary to understand mechanisms before taking steps to prevent an occupational or environmental disease, and too great a focus on mechanisms alone, though scientifically interesting, may distract from applying preventive measures.
The nanoparticles are carrying the unique toxic properties that are mainly cause health impact by spread through air pollution. Coal smoke and a winter temperature are a lethal combination. In December 1952, there was London smog which leads to more than 4000 deaths within a week. The reason behind death was Lung disease, chronic bronchitis, but it was apparent that a proportion was from heart attacks.
That was demonstrated; over half of the particles in London smog were less than 0.1 mm in diameter. This observation was unnoticed for longer time as 25 years, but in the 1990s two researches give the idea that are: epidemiological studies tells that even at low mass concentrations the deaths and particulate air pollution was occurred and studies of deposition of inhaled particles in the lungs of rats led to the observation that particles in the nanosize range were retained in the lungs and translocated to the interstitial tissues more readily than larger particles. From all of that it was understand that majority of deaths that link to the air pollution are due to the cardiac rather than respiratory and it can explain by the fact that toxicologically tiny doses of particulate matter (PM), mainly carbon, accumulate to the lungs cause death from failure of another organ by proposing the hypothesis that the effect was a consequence not of the mass of particles but of the number. This happens by the particles evaded the lungs and primary activate defense system, and release cytokinins which cause inflammation in the interstitial space and alteration of the coagulability of the blood. This rather complex idea, generally called the ultrafine hypothesis, triggered a change in the way toxicologists were to investigate air pollution, with an emphasis on the role of particles in the nanosize range.
The population exposure to air pollution arises the risk of death from heart disease in that population suggesting that air pollution, like cigarette smoking, leads to the development of coronary artery disease in which the progressive obstruction in the arterial wall arises which is a condition of atheroma. After rupturing of Atheromatous plaques the content releases that precipitating thrombosis and leads to the development of the acute coronary syndrome. Generally in atherogenesis inflammation is involved, but in the plaque various particles and inflammatory activity produces the cross-link between pulmonary inflammations. By this process air pollutants develop various chronic disorders.
The human may expose to the approximately 720 µg of particulate matter (PM) daily as they breathing in an urban area. A single cigarette introduces Approximat15,000 to 40,000 μg particle are accumulated in the respiratory tract of the smoker by taking a single cigarette. It is subsequently confounding why such a relatively small mass of airborne PM should have any biological effect in the patient with COPD, as these individuals are repeatedly exposed to particles (with a similar size and composition) at perhaps a thousand fold the mass of ambient PM.