Levels Of Volatile N-nitrosamines Research Articles

Characteristics and health risk assessment of volatile N-nitrosamines in the plasma of adults in Guangdong Province, China

N-nitrosamines are strong carcinogens that are widely present in the environment. This study developed a method, and analyzed the concentrations of volatile N-nitrosamines (VNAs) in the plasma of adults in Guangdong Province, China. Finally, the health risks to adults in Guangdong Province, China, with dietary exposure to VNAs were assessed. Gas chromatography/mass spectrometry (GC/MS) in electron impact (EI) ionization source mode was used to quantitatively analyze VNAs, and to perform accurate mass determination. The lower limit of detection (LOD) of nine nitrosamines are ranged from 0.01 to 2.14 ng/mL. The recovery rate ranged from 83 % to 116 %, and the relative standard deviation (RSD) was < 10 %. The method developed is simple, rapid, and provides good reproducibility and high sensitivity. N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodinbutylamine (NDBA), N-nitrosopiperidine (NPIP), N-nitrosopyrrolidine (NPYR), N-nitrosomorpholine (NMOR) and N-nitrosodiphenylamine (NDPhA) were detected in 92 adult plasma samples. NDMA and NMEA were detected in 56.5 % and 44.6 % of the samples, followed by NPIP (34.8 %). NDMA had the highest median concentration (43.7 ng/mL) in the total samples. There were gender-related differences found in the concentrations of NDBA and NDPhA. The exposure risk assessment results showed that the two highest daily dietary intakes of VNAs were N-nitrosodi-n-propylamine (NDPA) and NDMA, and aquatic products and pickled vegetables contributed the most total nitrosamine intake. The lifetime cancer risk of adults ranged from 2.88 × 10−10 to 7.46 × 10−5, and the risk associated with NDMA, NDPA, N-nitrosodiethylamine (NDEA), NMEA and NPIP are important and should attract more attention. This study aimed to explore the exposure levels of VNAs in the plasma of adults in Guangdong Province, China, and to assess the health risks of dietary intake of VNAs, which provides a basis of the effect of VNAs exposure on human health.

Mean daily intake of volatile N-nitrosamines from foods and beverages in West Germany in 1989–1990

The levels of volatile N-nitrosamines were determined in 38 alcoholic drinks and 215 food samples prepared for human consumption using standard culinary practices. The analyses used gas chromatography thermal energy analysis. Detectable levels were found in 80 (31.5%) of the individual samples. The average daily intake of voltaile N-nitrosamines in West Germany in 1989–1990 was found to be: 0.28 μg N-nitrosodimethylamine (NDMA)/day, 0.011 μg N-nitrosopyrrolidine (NPYR)/day and 0.015 μg N-nitrosopiperidine (NPIP)/day for men, and 0.17 μg NDMA/day, 0.011 μg NPYR/day and 0.015 μg/NPIP/day for women. For men, 31% of the daily NDMA exposure results from the consumption of beer.

Volatile N-nitrosamines in urinary catheters.

Levels of volatile N-nitrosamines were measured in 10 brands of latex and 2 brands of silicone catheters using high performance liquid chromatography. The cytotoxicity of catheters from identical batches was determined by measuring the inhibitory effect of catheter extracts on the uptake of 3H-labelled thymidine into L-929 fibroblasts in culture (IC50). The most frequently encountered nitrosamines were N-nitrosodi-n-butylamine and N-nitrosodiethylamine. Total N-nitrosamine levels in excess of 100 ng/g were found in 6 of the 16 catheters tested. When compared with the cytotoxicity of the catheters a significant correlation was found, with increasing nitrosamine content being associated with greater cytotoxicity. In view of the reported toxic and carcinogenic effects of these compounds it is suggested that the nitrosamine content of catheters be routinely monitored and safe regulatory limits be imposed.

Current Trends in Levels of Volatile N-Nitrosamines in Fried Bacon and Fried-Out Bacon Fat

Commercially processed bacon samples purchased from the Washington, DC, retail market have been periodically analyzed since 1971 for the presence of volatile N-nitrosamines in the fried product. During that time, a downward trend in the concentration of N-nitrosopyrrolidine has been observed, and between 1978 and 1980 it plateaued at 4-30 ppb, with an average of 11 ppb. A recent survey, however, indicates a change in this downward trend, with N-nitrosopyrrolidine found at levels ranging from 1 to 65 ppb, average 21 ppb. Volatile N-nitrosamines were found at levels up to 110 ppb in the fried product and up to 85 ppb in the fried-out bacon fat.

魚粉における揮発性ニトロサミンの存在および生成 Ｉ 市販魚粉より検出された揮発性ニトロサミン

Volatile N-nitrosamines (VNA) in 32 commercial fish meal samples were analyzed by a gas chromatograph equipped with a thermal energy analyzer (GC-TEA), and three different VNA, N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR) and N-nitrosothiazolidine (NTHZ) were detected in these samples in common. The VNA levels were apparently varied depending on the method of preparation, particularly on the drying system of meals. The VNA levels in fish meals which had been dried by blowing hot air exhausted from an oil burner (direct heating-drying type) were found to be much higher than those dried by a steam heating drier system (indirect drying type). The reason for high levels of VNA in the meals prepared by direct heating-drying system might be associated with the higher NOX concentration in the heating air. As to the components of VNA in fish meal samples, the quantities of NDMA were the highest, followed by those of NPYR and NTHZ. The NDMA contents in the direct heating-drying type of fish meals were fairly high, and the maximum value was as much as 1400μg/kg. The mean value of NDMA in this type of meals was about 40times higher than that of NPYR, and 80times that of NTHZ. It was noted that carcinogenic N-nitrosomorpholine (NMOR) could he detected in two samples, although the migration route of morpholine, the precursor of NMOR, into these samples remained unclarified.

Reduction in levels of volatile N-nitrosamines in rubber nipples for babies' bottles

Levels of volatile N-nitrosamines were determined in 189 samples of rubber nipples for babies' bottles. Domestic (US-manufactured) and imported rubber nipples for consumer and hospital use were analysed to determine compliance with the US Food and Drug Administration's action level of 60 ppb (b = 10 9) for total volatile N-nitrosamines. Only one sample was found to be in violation of the action level; it contained a total of 137 ppb N-nitrosamines.

N-nitrosamines in snuff and chewing tobacco on the Swedish market in 1983.

Snuff and chewing tobacco on the Swedish market in 1983 were analysed for tobacco-specific and volatile N-nitrosamines using gas chromatography--thermal energy analysis. All 36 samples of snuff analysed were found to contain detectable levels of N'-nitrosonornicotine, N'-nitrosoanatabine, N'-nitrosoanabasine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Total tobacco-specific N-nitrosamine levels between 2.5 and 51 mg/kg wet weight were found, the mean level being 8.8 mg/kg. Detectable levels of at least two of the four tobacco-specific N-nitrosamines were found in all 18 samples of chewing tobacco analysed. The total concentration of tobacco-specific N-nitrosamines found in chewing tobacco was between 0.1 and 7.8 mg/kg, the mean level being 2.1 mg/kg. The levels of volatile N-nitrosamines found in the 54 samples of snuff and chewing tobacco were very much lower--most of the samples contained less than 10 micrograms/kg and the highest concentration found was 550 micrograms/kg. Since snuff and chewing tobacco contain relatively high levels of carcinogenic N-nitrosamines and there is evidence of an association between the use of these tobacco products and human cancer, snuff and chewing tobacco users should be warned about the possible cancer risk involved in their habit. In addition, efforts should be made to reduce the levels of N-nitrosamines in snuff and chewing tobacco and the formation of these substances in the body from precursors originating from these tobacco products.