Natural Water and Drinking Water Containing N-nitrosamines and the Regional Cancer Incidence in the Pearl River Delta
Abstract
The regional characteristics of cancer morbidity and mortality in China are obvious. The Pearl River Delta region is a region with high incidence of nasopharyngeal carcinoma and liver cancer. Before the local industrial pollution, the incidence of cancer in this region was significantly higher than that in other regions of China. Researchers have put forward various etiological factors from the perspectives of medicine, geography, ecological environment, genetics, and so on. The two mainstream ones are: 1. Special lifestyle factors. Local residents usually eat pickled food, such as salted fish and pickled vegetables. 2. Ecological and environmental factors, such as the original pollution of the soil and local food in the region, and the pollution of trace elements, Water nitrite et al. in 1989 N-nitrosamine was first reported in drinking water in Ontario, Canada. N-nitrosamine is the most dangerous substance that causes cancer. Previous studies in Guangdong Province showed that underground forests (buried in large numbers of ancient tree-plants) developed underground in the Pearl River Delta region. A significant part of the plant has been transformed, This study attempts to investigate the relationship between excessive nitrosamine content in various natural water bodies, drinking water, surface soil and local edible plants and meat, and the incidence of cancer.
Because of the very low content of N-nitrosamine in natural water and drinking water, It is very difficult to measure the content of samples by the previous analytical method of nitrosamines. We have successfully developed a new analytical method for the determination of ultra-low trace nitrosamines in water by solid-phase extraction-gas chromatography-tandem mass spectrometry. The point is to extract and concentrate nitrosamines in samples by solid phase extraction with coconut shellactivated carbon, and then to determine 9 nitrosamines by GC-MS/MS. In Shunde and Sihui areas of the Pearl River Delta, Guangdong Province, groundwater (hand-pressed well water and deep drilling water, spring water, surface water (fish pond water, ditch water, river water, etc.) and drinking water (simple tap water in rural areas) were collected . A total of 75 water samples were collected in the study area. Nine kinds of nitrosamines were analyzed with a new method, and a total of 675 data were obtained. The highest content of nitrosamine is 307 ng / L, the lowest is 0.34 ng / L, and the total detection rate of nitrosamines in various water bodies is 40%. The hygienic standard of N- nitrosamine in drinking water is 10 ng / L(Germany), and the overall rate of exceeding the standard is 15%, of which the excess rate of drinking water samples is 12%. Statistic results of water samples N-nitrosamines contents with different water-body types The average value, peak value and detection rate of nitrosodimethylamine (NDMA) and nitrite dibutylamine (NDBA) are the highest in all of samples. The secondary compounds were nitroso diphenylamine (NDPhA) and nitropiramidon (NPYR).Five other nitrosamines, such as nitrosodiethylamine (NDEA), had low detectable numbers, and some of them had high values or exceeded the standard. River water and fish pond water detection and exceed the standard rate is the most serious. The results confirm that many current drinking water systems, household tap water nitrosamines exceed the standard(10 ng / L), the overall statistics, including hand-wells and discarded well water samples of nitrosamines exceeded the standard rate of 12%. Statistic results of water samples for 6 N-nitrosamines contents in the different sick regions. Shunde area is the city with the highest detection and exceeding standard of various nitrosamines in the study. The peak values of five kinds of nitrosamines, such as NDMA and NDBA, are seriously exceeded the standard, which overlapped with the high cancer incidence areas in Shunde. The high detection of NDMA and NDBA were found in Sihui area, the peak value and the mean value are over the standard. Sihui was the typical high incidence area of nasopharyngeal carcinoma in the Pearl River Delta. The new method improves the detection sensitivity of N-nitrosamines in water and environment, and the detection limit is 0.34-2.19 ng / L, which is suitable for the determination of nine kinds of N-nitrosamines in natural water and drinking water. N- nitrosamines were first found in the environment and drinking water of cancer areas in the Pearl River Delta. The highest content of nitrosamine is: 307ng / L, the lowest is 0.34 ng / L; the detection rate of N- nitrosamine in the sample is 40. According to the hygienic standard of N- nitrosamine in drinking water in Germany, the overall rate of exceeding the standard is 15, and the rate of exceeding the standard of drinking water sample is 12. The nitrosamine-containing groundwater is a kind of ammonium rich nitrogen water, which is easy to react with nitrite to form N-nitrosamine under the condition of acidic weak oxidation and rich organic matter. The results of water sample analysis showed that the average content of nitrosamines in Shunde area is the highest. The pollution of N- nitrosamine in environment and drinking water in Shunde area is the most serious. The area polluted by N- nitrosamine overlapped with the incidence of liver cancer in this area.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMGH33C1267K
- Keywords:
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- 0478 Pollution: urban;
- regional and global;
- BIOGEOSCIENCESDE: 0815 Informal education;
- EDUCATIONDE: 1094 Instruments and techniques;
- GEOCHEMISTRYDE: 0240 Public health;
- GEOHEALTH