RESUMEN
The prevalence of carcinogenic N-nitrosamines in drinking water is of significant concern. In the present study, eight N-nitrosamines from three representative drinking water treatment plants (DWTPs) in Shanghai, China were monitored for an entire year to evaluate their seasonal variability, probabilistic cancer risk and the resulting disease burden. The possibility of employing routinely monitored water quality parameters as predictors of N-nitrosamines was also examined. The results showed that the Taipu River-fed reservoir suffered more serious N-nitrosamine contamination than the Yangtze River-fed reservoirs. Winter witnessed higher levels of N-nitrosamines in both source and finished water. N-nitrosamine concentrations increased from source water to finished water in autumn or winter, but no spatial variations were observed in summer. The total lifetime cancer risk (LCR) posed by N-nitrosamines in finished water was within the acceptable range (1.00 × 10-6 to 1.00 × 10-4), with N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) being the main contributors. Winter and autumn were found to have higher total LCR values. The average individual disability-adjusted life years (DALYs) lost was 4.43 × 10-6 per person-year (ppy), exceeding the reference risk level (1.00 × 10-6 ppy). Liver cancer accounted for 97.1 % of the total disease burden, while bladder and esophagus cancers made a little contribution (2.9 %). A multiple regression model was developed to estimate the total N-nitrosamines in finished water as a function of water quality parameters, and the R2 value was 0.735. This study not only provides fundamental data for public health policy development, but also reveals the necessity to incorporate a seasonal control strategy in DWTPs to minimize the associated health risks induced by N-nitrosamines.
Asunto(s)
Agua Potable , Neoplasias , Nitrosaminas , Contaminantes Químicos del Agua , Humanos , Contaminantes Químicos del Agua/análisis , Estaciones del Año , China , Nitrosaminas/análisis , Neoplasias/inducido químicamente , Neoplasias/epidemiologíaRESUMEN
OBJECTIVE: To understand the health status and influencing factors of people in bathing beach after bathing. METHODS: A questionnaire survey was conducted among the beach tourists in Hebei, Shandong and Shanghai Provinces from May to September, 2019-2020, including personal basic information, seawater/beach exposure in the last 7 days, beach activities, personal protective measures, physical health, related symptoms or diseases after bathing, etc. The seawater samples and sand of the three bathing beaches were sampled and detected. RESULTS: A total of 1222 valid questionnaires were collected. Skin infection(26. 19%), nasal congestion(12. 36%) and eye infection(8. 18%) were the most common symptoms of the tourist after seawater bath. Multivariate logistic regression analysis showed that previous physical discomfort(OR=0. 08-140. 73, 95%CI 0. 04-443. 64) was the common factor of all symptoms(P& lt; 0. 05), the risk factors of stomach cramps, eye infection, nasal congestion and sore throat were no wear of turbinate(OR=4. 65, 95% CI 1. 53-14. 08) and goggles(OR=541. 52, 95% CI 121. 58-2411. 85), swallowing seawater(OR=2. 29-79. 78, 95%CI 19. 83-296. 78) respectively(P& lt; 0. 05). CONCLUSION: Personal protective measures and physical conditions affect people& apos; s symptoms and diseases after bathing. There is microbial pollution in beach water and sand.
Asunto(s)
Playas , Microbiología del Agua , China/epidemiología , Ciudades , Monitoreo del Ambiente , Humanos , Agua de Mar , AguaRESUMEN
OBJECTIVE: The aim of this study was to perform an exposure assessment of PM2.5 (particulate matter less than 2.5µm in aerodynamic diameter) among children and to explore the potential sources of exposure from both indoor and outdoor environments. METHODS: In terms of real-time exposure measurements of PM2.5, we collected data from 57 children aged 8-12 years (9.64 ± 0.93 years) in two schools in Shanghai, China. Simultaneously, questionnaire surveys and time-activity diaries were used to estimate the environment at home and daily time-activity patterns in order to estimate the exposure dose of PM2.5 in these children. Principle component regression analysis was used to explore the influence of potential sources of PM2.5 exposure. RESULTS: All the median personal exposure and microenvironment PM2.5 concentrations greatly exceeded the daily 24-h PM2.5 Ambient Air Quality Standards of China, the USA, and the World Health Organization (WHO). The median Etotal (the sum of the PM2.5 exposure levels in different microenvironment and fractional time) of all students was 3014.13 (µg.h)/m3. The concentration of time-weighted average (TWA) exposure of all students was 137.01 µg/m3. The median TWA exposure level during the on-campus period (135.81 µg/m3) was significantly higher than the off-campus period (115.50 µg/m3, P = 0.013 < 0.05). Besides ambient air pollution and meteorological conditions, storey height of the classroom and mode of transportation to school were significantly correlated with children's daily PM2.5 exposure. CONCLUSIONS: Children in the two selected schools were exposed to high concentrations of PM2.5 in winter of 2013 in Shanghai. Their personal PM2.5 exposure was mainly associated with ambient air conditions, storey height of the classroom, and children's transportation mode to school.
Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Exposición a Riesgos Ambientales/análisis , Material Particulado/análisis , Contaminación del Aire Interior/análisis , Niño , China , Monitoreo del Ambiente , Femenino , Humanos , Masculino , TransportesRESUMEN
OBJECTIVE: To observe the relationship between urinary metallothionein excretion and osteal damage induced by cadmium in a general population. METHODS: The inhabitants living in both cadmium polluted and non-polluted areas were asked to participate in this study. Urinary cadmium (UCd) and blood cadmium (BCd) were measured by GF-AAS. Total cadmium(TCd)was evaluated with environmental cadmium exposure. URBP, UB2M, UALB and UMT were measured by ELISA method. UNAG, UNAGB were measured by fluorescence analysis method. Forearm bone mineral density in human were mensurated by SPA. RESULTS: UMT can reflect the change of cadmium body burden. Renal dysfunction and osteoporosis would appear successively after high level of cadmium exposure. UMT had a complex relationship with bone mineral density which related to the amount of UMT excretion. The BMDLs of UCd were calculated using software of BMDS Versionl. 3.2 for these biomarkers. The values of BMDL of these biomarkers were arranged: UNAGB < UNAG < UB2M < UMT < URBP < Tscore < UALB. CONCLUSION: Cadmium exposure could induce bone damage which occurred later than renal dysfunction related to cadmium exposure. UMT could be not only a specific and sensitive biological indicator of cadmium-induced renal dysfunction but also could reflect the damage on bone induced by cadmium.
Asunto(s)
Enfermedades Óseas/inducido químicamente , Enfermedades Óseas/orina , Cadmio/toxicidad , Exposición a Riesgos Ambientales/efectos adversos , Metalotioneína/orina , Adulto , Anciano , Biomarcadores/orina , Densidad Ósea , Cadmio/sangre , Cadmio/orina , Femenino , Humanos , Enfermedades Renales/inducido químicamente , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: Based on two sets of data from occupational epidemiology, Benchmark dose (BMD) was applied to estimate biological exposure limit (BEL). METHODS: Cadmium exposed workers were selected from a cadmium smelting and a zinc products factory and control group was selected from doctors or nurses and staff from shops living in the same area; Urinary cadmium (UCd) was used as exposure biomarker and urinary beta(2) microglobulin (UBM), NAG (UNAG) and albumin (UALB) were as effect biomarkers. All urine parameters were adjusted by urinary creatinine. Software of BMDS (Version 1.3.2, EPA.U.S) was used to calculate BMD. RESULTS: Calculated abnormal prevalence was based on the upper limit of 95% of effect biomarkers in control group; There are significant dose response relationship between the prevalence of effect biomarkers (UBM, UNAG and UALB) and exposure biomarker (UCd); BEL was 5 microg/g creatinine for UBM as effect biomarker, It consists with the recommendation of WHO; BEL was 3 microg/g creatinine for UNAG as effect biomarker; BEL can be estimated by using the method of BMD; the more sensitive biomarker would used, the more occupational people would protected. CONCLUSION: The application of BMD in estimating biological exposure limit (BEL) is proper. UNAG is suggested as most sensitive biomarker to be used to estimate BEL for cadmium exposure.
Asunto(s)
Cadmio/orina , Exposición Profesional , Acetilglucosaminidasa/orina , Albuminuria/orina , Biomarcadores/orina , Cadmio/efectos adversos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Valores de Referencia , Microglobulina beta-2/orinaRESUMEN
OBJECTIVE: To estimate the benchmark dose for osteoporosis caused by cadmium exposure in a Chinese general population with an epidemiological study. METHODS: The inhabitants living in both cadmium polluted and non-polluted areas served as the exposure group and the control group. Urinary cadmium (UCd) and Blood cadmium (BCd) were used as exposure biomarkers while the Z score was used as effect biomarker for the osteoporosis. RESULTS: The UCd and BCd in the habitants of the polluted areas were significantly higher than those in the habitants of the control area on average (P < 0.05) and the UCd and BCd in the habitants of the highly polluted areas were significantly higher than those in the habitants of the moderately polluted area on average (P < 0.05). The bone mineral density was significantly decreased in the groups of the highest UCd and BCd level compared with the 5 microg/g Cr group with the significant difference (P < 0.05). The morbidity of the osteoporosis would increase significantly with the increase of the cadmium exposure (P < 0.05) with the linear correlation (P < 0.05). BMDs were calculated using BMDS Version l.3.2 software and BMDLs were also determined. The BMDL of UCd for cadmium-induced osteoporosis was higher than those representing cadmium-induced renal dysfunction. CONCLUSION: High level of cadmium exposure can induce osteoporosis, which occurs later than renal damage related to cadmium exposure. The BMD is a practical method.