Industrial Pollutants and Nasopharyngeal Cancer: An Open Question

INTRODUCTION AND OBJECTIVES: Nasopharyngeal Carcinoma represents 0.7% of the total cancer cases in the world with an ASR index of 1.7 and is widely associated with Epstein-Barr virus. It is not common in Italy (ASR index of 0.5) while in China (ASR 1.9), one third of the clinical cases are observed in Guangdong (ASR index 11.3). It is also quite common in Malaysia and Indonesia. The activation of the cancerogenesis process happens after the exposure to some environmental parameters that epidemiological studies have indicated with various dietary habits, mainly for salted fish consumption. The purpose of this work is to highlight such as exposure to compounds, such as formaldehyde, which is present in the different working conditions of these countries and may lead to the real cause to establish the carcinogenic process.

MATERIALS AND METHODS: The most recent publications regarding the impact of various external factors on Pub Med, Google, TOXLINE, Chem Abstract, were analyzed with the radiological data that were found in Milan hospitals database.

RESULTS: The relationship between food consumption and nasopharyngeal cancer are not clear and statistically insignificant in Indonesia. In Malaysia, the preparation of natural rubber for the use of formaldehyde is a dangerous environmental factor. The same exposure is a risk factor in Guangdong, where many workers are employed in the wood panel industry. Incidence of cancer in these Chinese ethnic groups decreases when they migrate to other countries. In the last 5 years, few cases were recorded in Italy, without any apparent change in ethnic environmental factors or HBV infection Discussion: In the production of natural rubber, a lot of people are exposed to formaldehyde during the various steps of preparation and production such as stripping, drying and coagulation without observing proper environmental hygiene precautions. The same working conditions are present in industrial production of wood panels in Guangdong, China. The relationship between exposure to formaldehyde and nasopharyngeal cancer is demonstrated by the fact that epidemiological studies on the population of this Chinese district whose immigrant populations were not exposed to these pollutants, the appearance of these tumors decreases. Also an examination of our radiological data in Italy shows that in about one hundred sixty cases of nasopharyngeal cancer none of the patients were Indonesian or Chinese Conclusion: The preliminary results of our study suggest that EPST-BARR virus could be a risk factor if associated with exposure to compounds such as formaldehyde which is present in industrial productions of countries like Indonesia, Malaysia, and China.