Lung Carcinogenic Bioassay of CuO and TiO2 Nanoparticles with Intratracheal Instillation Using F344 Male Rats

Toxicity assessment of nanoparticles, now widespread in our environment, is an important issue. We have focused attention on the carcinogenic potential of copper oxide (CuO) and titanium dioxide (TiO2). In experiment 1, a sequential pilot study, the effectiveness of a carcinogenic bioassay featuring intraperitoneal injection (i.p.) of 20 mg 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) or 0.1% N-bis(2-hydroxypropyl)nitrosamine (DHPN) in drinking water for 2 weeks was examined. Based on the results, DHPN, as the lung carcinogen, and evaluation at week 30 were selected as the most appropriate for our purposes in Experiment 1. In experiment 2, the carcinogenic bioassay was used to assess the carcinogenic potentials of instilled nanoparticles of CuO and TiO2. There were no significant intergroup differences in the lung neoplastic lesions induced by DHPN, although the neoplastic lesions induced by the nanoparticles in the CuO or TiO2 intratracheal instillation (i.t.) groups, demonstrated a tendency to increase compared with the microparticles administration. At the very least, the carcinogenic bioassay with DHPN proved useful for assessment of the modifying effects of instilled particles, and further assessment of the carcinogenic potential of nanoparticles appears warranted

Cancer is a Preventable Disease that Requires Major Lifestyle Changes

This year, more than 1 million Americans and more than 10 million people worldwide are expected to be diagnosed with cancer, a disease commonly believed to be preventable. Only 5–10% of all cancer cases can be attributed to genetic defects, whereas the remaining 90–95% have their roots in the environment and lifestyle. The lifestyle factors include cigarette smoking, diet (fried foods, red meat), alcohol, sun exposure, environmental pollutants, infections, stress, obesity, and physical inactivity. The evidence indicates that of all cancer-related deaths, almost 25–30% are due to tobacco, as many as 30–35% are linked to diet, about 15–20% are due to infections, and the remaining percentage are due to other factors like radiation, stress, physical activity, environmental pollutants etc. Therefore, cancer prevention requires smoking cessation, increased ingestion of fruits and vegetables, moderate use of alcohol, caloric restriction, exercise, avoidance of direct exposure to sunlight, minimal meat consumption, use of whole grains, use of vaccinations, and regular check-ups. In this review, we present evidence that inflammation is the link between the agents/factors that cause cancer and the agents that prevent it. In addition, we provide evidence that cancer is a preventable disease that requires major lifestyle changes