首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
During precipitation events, untreated human sewage is often intentionally discharged to surface water bodies via combined sewer overflow (CSO) systems in order to avoid overloading wastewater treatment plants. The purpose of this analysis was to evaluate the risk of pathogen-related disease associated with CSO discharges into the Lower Passaic River. Concentrations of fecal coliform, total coliform, fecal Streptococcus, and fecal Enterococcus bacteria were measured at six river locations on six different days in 2003 (n = 36). In addition, water samples (n = 2) were collected directly from and in the immediate vicinity of a discharging CSO in Newark, NJ. These samples were analyzed for fecal coliforms, total coliforms, fecal Streptococcus, fecal Enterococcus, Giardia lamblia, Cryptosporidium parvum, and several viruses. Risk estimates for gastrointestinal illness and Giardia infection resulting from indirect and direct ingestion of contaminated water were calculated for three potential exposure scenarios: visitor, recreator, and homeless person. Single-event risk was first evaluated for the three individual exposure scenarios; overall risk was then determined over a 1-year period. Monte Carlo techniques were used to characterize uncertainty. Nearly all of the pathogen concentrations measured in the Passaic River exceeded health-based water quality criteria and in some cases were similar to levels reported for raw sewage. The probability of contracting gastrointestinal illness due to fecal Streptococcus and Enterococcus from incidental ingestion of water over the course of a year ranged from 0.14 to nearly 0.70 for the visitor and recreator scenarios, respectively. For the homeless person exposure scenario, the risk for gastrointestinal illness reached 0.88 for fecal Streptococcus and Enterococcus, while the probability of Giardia infection was 1.0. This risk analysis suggests that, due to the levels of pathogens present in the Lower Passaic River, contact with the water poses, and will continue to pose, significant human health risks until CSO discharges are adequately controlled or abated.  相似文献   

2.
Analytical results for Aroclor may contain a great deal of uncertainty if the relative ratios of certain PCB congeners are substantially altered following differential environmental degradation. Selective degradation of PCB congeners has been shown to occur in biological tissues, and recent studies have shown that Aroclor analyses may significantly underestimate PCB concentrations in fish. The purpose of this study is to assess whether a similar phenomenon can occur with PCB-impacted sediments. Five hundred and thirty-seven sediment samples from the Passaic River were analyzed for Aroclors and selected non-ortho (PCB #77, 126, and 169) and mono-ortho (PCB #105, 114, 118, 123, 156, 157, 167, and 189) coplanar PCB congeners. Aroclors 1248 and 1254 were detected in 67 and 53% of the samples, respectively; 54 samples (approximately 10%) did not contain detectable levels of any Aroclors. In these 54 samples, the sum of the detected PCB congener concentrations was significantly greater, on average, than the Aroclor limit of detection by approximately threefold. In individual samples the sum of the PCB congeners exceeded the Aroclor limit of detection by up to 36-fold. In those samples in which Aroclors were detected, the summed PCB congener concentrations exceeded the Aroclor 1248 and 1254 concentrations, on average, by 41 and 33%, respectively. Given the fact that only a fraction of the 209 PCB congeners were quan-titated, these findings indicate that Arocolor data may significantly underestimate total PCB concentrations in Passaic River sediments. Total PCB data obtained from total homologue analysis indicated that Aroclor results underestimated total PCB mass by up to 43-fold. These findings suggest that caution is required when comparing Aroclor sediment data from the Passaic River to total PCB sediment criteria.  相似文献   

3.
4.
Maternal exposure to an immune challenge can convey enhanced immunity to invertebrate offspring in the next generation. We investigated whether maternal exposure of the Asian longhorned beetle, Anoplophora glabripennis, to two species of the fungus Metarhizium or the bacterium Serratia marcescens elicited transgenerational immune priming (TGIP). We tested specificity of this protection and whether occurrence of TGIP was dependent on maternal exposure to living versus dead pathogens. Our results show that TGIP occurred and protected offspring against Metarhizium brunneum. Maternal exposure to S. marcescens provided non-specific protection to offspring against a fungal pathogen, but TGIP in response to Metarhizium only occurred when offspring were exposed to the same fungal species that was used to prime mothers. Moreover, TGIP in response to M. brunneum occurred only after maternal exposure to living rather than dead fungus. Our findings suggest that occurrence of TGIP could be both specific and dependent on whether the pathogen was alive.  相似文献   

5.
A historical impact assessment was conducted for chemical contaminants in sediments of the tidal Passaic River in northern New Jersey. The assessment was based on sediment cores collected from 1990 to 1995. Each sediment core was segregated into fractions and the fractions dated using radioisotope analysis. Chemical concentrations, including a variety of metals and organic compounds, were estimated by decade for most of the 20th century in five reaches of the River. The chemical data for each decade were compared to available benchmark sediment quality values that represent levels of chemicals that may be toxic to benthic invertebrates in estuarine systems. Benchmark exceedances in the River were then calculated and characterized spatially and temporally using quantitative Geographic Information System (GIS) analyses, and the area of “impacted” sediments was calculated for each chemical and decade. Results of this assessment suggest that the ability of Passaic River sediments to support “normal” benthic invertebrate populations was limited by sediment contaminants throughout the 20th century. Conditions have improved somewhat since the 1950s, although impacts to benthic populations remain from several metals and organic compounds despite some overall improvements in sediment quality in recent years.  相似文献   

6.
7.
Arithmetic and lognormal means historically have been used as estimates of exposure concentration for both human health and ecological risk assessment. Past risk assessment guidance has emphasized the need to include all available informa tion, particularly regarding the spatial and temporal aspects of data and exposure. One estimate of exposure concentration that includes spatial information is the 95% upper confidence limit (UCL) of the area weighted mean. An area weighted mean is calculated using weightings based on the ratio of the area associated with a sample location and the total area of the study area. Currently, U.S. Environmental Protection Agency (USEPA) risk assessment guidance recommends the use of the 95% UCL of the arithmetic mean as the most appropriate measure of exposure concentration for soil and sediment in human health and ecological risk assess ments. The purpose of this study was two fold: (1) to evaluate the use of the 95% UCL of the area weighted mean vs. the 95% UCL of the arithmetic mean for the lognormal distribution and the normal distribution using a large data set from a recent riverine sediment characterization study, and (2) to evaluate the potential associated with the different approaches for reduction in surface sediment exposure concentrations for 2,3,7,8 TCDD and coplanar polychlorinated biphenyls (PCBs) for several subsets of the data. The results of this evaluation indicated that there was no significant reduction in exposure concentrations of the study area surface sediments after any of the selected higher concentration data points had been removed from the various data subsets. In addition, this evaluation indicated that, due to its dependence on the variance of the data, the 95% UCL of the arithmetic mean for a lognormal distribution produced subset exposure concentrations that were higher than the calculated concentrations of the full data set and produced the smallest percent changes in concentration compared to the other two measures. Based on this analysis, the 95% UCL of the area weighted mean was determined to be the most stable and appropriate estimator of exposure concentration for surface sediments.  相似文献   

8.

Background

Isotretinoin (13-cis retinoic acid) is a metabolite of vitamin A and has anti-inflammatory and immunoregulatory effects; however, a recent publication by DePaolo et al. demonstrated that in the presence of IL-15, retinoic acid can act as an adjuvant and promote inflammation against dietary proteins.

Objective

To evaluate the risk of overt and latent celiac disease (CD) among users of isotretinoin.

Material and Methods

Medical records of patients from 1995 to 2011 who had a mention of isotretinoin in their records (N = 8393) were searched for CD diagnosis using ICD-09CM codes. Isotretinoin exposure was compared across overt CD patients and their age- and gender-matched controls from the same pool. To evaluate the risk of latent CD with isotretinoin exposure, patients were overlapped with a community-based list of patients with waste serum samples that were tested for CD serology, excluding those with overt CD (2006–2011). Isotretinoin exposure was defined as the use of isotretinoin prior to CD diagnosis or serology.

Results

Of 8393 patients, 25 had a confirmed CD diagnosis. Compared to matched controls (N = 75), isotretinoin exposure was not significantly different between overt CD patients versus controls (36% versus 39%, respectively; P = 0.712). Likewise, latent CD defined as positive serology was not statistically different between isotretinoin exposed (N = 506) versus non-exposed (N = 571) groups (1.8% versus 1.4%, respectively; P = 0.474).

Conclusions

There was no association between isotretinoin use and risk of either overt or latent CD.  相似文献   

9.
《Endocrine practice》2020,26(11):1312-1319
Objective: Iodine 131 (I-131) radioactive iodine (RAI) therapy has been the preferred treatment for Graves disease in the United States; however, trends show a shift toward antithyroid drug (ATD) therapy as first-line therapy. Consequently, this would favor RAI as second-line therapy, presumably for ATD refractory disease. Outcomes of RAI treatment after first-line ATD therapy are unclear. The purpose of this study was to investigate treatment failure rates and potential risk factors for treatment failure, including ATD use prior to RAI treatment.Methods: A retrospective case control study of Graves disease patients (n = 200) after I-131 RAI therapy was conducted. Treatment failure was defined as recurrence or persistence of hyperthyroidism in the follow-up time after therapy (mean 2.3 years). Multivariable regression models were used to evaluate potential risk factors associated with treatment failure.Results: RAI treatment failure rate was 16.5%. A majority of patients (70.5%) used ATD prior to RAI therapy, predominantly methimazole (MMI) (91.9%), and approximately two-thirds of patients used MMI for >3 months prior to RAI therapy. Use of ATD prior to RAI therapy (P = .003) and higher 6-hour I-123 thyroid uptake prior to I-131 RAI therapy (P<.001) were associated with treatment failure. MMI use >3 months was also associated with treatment failure (P = .002).Conclusion: More patients may be presenting for RAI therapy after failing first-line ATD therapy. MMI use >3 months was associated with RAI treatment failure. Further studies are needed to investigate the association between long-term first-line ATD use and RAI treatment failure.  相似文献   

10.
11.
李燕斐  陈勤 《生命的化学》2007,27(5):431-433
药物成瘾所导致的行为和生理方面的长时程改变可能与相关脑区突触连接的重构有关。安非他命、可卡因、吗啡和尼古丁滥用时,精神依赖和奖赏效应相关脑区神经元的树突和树突棘的结构发生改变,这反映药物滥用致相关神经回路突触连接方式的改变。这种改变足长时程的、脑区特异性的,是多种因素调节的结果。  相似文献   

12.
The harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period. The identities of the dominant, indigenous, presumptive pathogenic isolates obtained from the rainwater samples throughout the sampling period were confirmed through universal 16S rRNA PCR, and the results revealed that Pseudomonas (19% of samples) was the dominant genus isolated, followed by Aeromonas (16%), Klebsiella (11%), and Enterobacter (9%). PCR assays employing genus-specific primers also confirmed the presence of Aeromonas spp. (16%), Klebsiella spp. (47%), Legionella spp. (73%), Pseudomonas spp. (13%), Salmonella spp. (6%), Shigella spp. (27%), and Yersinia spp. (28%) in the harvested rainwater samples. In addition, on one sampling occasion, Giardia spp. were detected in 25% of the eight tank water samples analyzed. This study highlights the diverse array of pathogenic bacteria that persist in harvested rainwater during high-rainfall periods. The consumption of untreated harvested rainwater could thus pose a potential significant health threat to consumers, especially children and immunocompromised individuals, and it is recommended that harvested rainwater be treated for safe usage as an alternative water source.  相似文献   

13.
14.

Background

The risk of periodontitis (PD) is increased in the patient group of rheumatoid arthritis (RA). RA and PD also shared some pathological mechanism. The aim of this study is to investigate the risk of RA associated with PD exposure.

Methods and Findings

This study identified 3 mutually exclusive cohorts using the 1999–2010 Taiwanese National Health Insurance Research Database (NHIRD) to investigate the association between PD and the risk of incident RA. All patients with PD in 2000 were identified from the database of all enrollees as the PD cohort. From the representative database of 1,000,000 enrollees randomly selected in 2010 (LHID2010), individuals without any periodontal disease (PO) during 1999–2010 were selected as the non-PO cohort. Individuals who were not included in the non-PO cohort and received dental scaling (DS) no more than two times per year during 1999–2010 were selected as the DS cohort from LHID2010. Using cox proportional regression analysis, hazard ratios (HRs) with 95% confidence intervals (Cis) were calculated to quantify the association between PD exposure and RA development. In the three-group comparison using the non-PO cohort as reference, we found that the risk of RA was higher in the PD and DS cohorts (HRs, 1.89 and 1.43; 95% CIs, 1.56–2.29 and 1.09–1.87, respectively). For comparisons between two cohorts, the PD cohort had a higher risk of RA than the non-PO and DS cohorts (HRs, 1.91 and 1.35; 95% CIs, 1.57–2.30 and 1.09–1.67, respectively).

Conclusion

PD was associated with an increased risk of RA development.  相似文献   

15.
Worldwide, Norway rats (Rattus norvegicus) carry a number of zoonotic pathogens. Many studies have identified rat-level risk factors for pathogen carriage. The objective of this study was to examine associations between abundance, microenvironmental and weather features and Clostridium difficile, antimicrobial-resistant (AMR) Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) carriage in urban rats. We assessed city blocks for rat abundance and 48 microenvironmental variables during a trap-removal study, then constructed 32 time-lagged temperature and precipitation variables and fitted multivariable logistic regression models. The odds of C. difficile positivity were significantly lower when mean maximum temperatures were high (≥ 12.89°C) approximately 3 months before rat capture. Alley pavement condition was significantly associated with AMR E. coli. Rats captured when precipitation was low (< 49.40 mm) in the 15 days before capture and those from blocks that contained food gardens and institutions had increased odds of testing positive for MRSA. Different factors were associated with each pathogen, which may reflect varying pathogen ecology including exposure and environmental survival. This study adds to the understanding of how the microenvironment and weather impacts the epidemiology and ecology of zoonotic pathogens in urban ecosystems, which may be useful for surveillance and control activities.  相似文献   

16.

Objective

To test the hypothesis that exposure to fine particulate air pollution (PM2.5) is associated with stillbirth.

Study Design

Geo-spatial population-based cohort study using Ohio birth records (2006-2010) and local measures of PM2.5, recorded by the EPA (2005-2010) via 57 monitoring stations across Ohio. Geographic coordinates of the mother’s residence for each birth were linked to the nearest PM2.5 monitoring station and monthly exposure averages calculated. The association between stillbirth and increased PM2.5 levels was estimated, with adjustment for maternal age, race, education level, quantity of prenatal care, smoking, and season of conception.

Results

There were 349,188 live births and 1,848 stillbirths of non-anomalous singletons (20-42 weeks) with residence ≤10 km of a monitor station in Ohio during the study period. The mean PM2.5 level in Ohio was 13.3 μg/m3 [±1.8 SD, IQR(Q1: 12.1, Q3: 14.4, IQR: 2.3)], higher than the current EPA standard of 12 μg/m3. High average PM2.5 exposure through pregnancy was not associated with a significant increase in stillbirth risk, adjOR 1.21(95% CI 0.96,1.53), nor was it increased with high exposure in the 1st or 2nd trimester. However, exposure to high levels of PM2.5 in the third trimester of pregnancy was associated with 42% increased stillbirth risk, adjOR 1.42(1.06,1.91).

Conclusions

Exposure to high levels of fine particulate air pollution in the third trimester of pregnancy is associated with increased stillbirth risk. Although the risk increase associated with high PM2.5 levels is modest, the potential impact on overall stillbirth rates could be robust as all pregnant women are potentially at risk.  相似文献   

17.
18.

Objectives

To determine the lower urinary tract symptoms (LUTS) profile and factors affecting its degree of severity including cardiovascular risk profile, age, ethnicity, education level and prostate volume in a multiethnic Asian setting.

Materials and Methods

We conducted a cross-sectional study of 1021 men aged 40–79 years with no clinical evidence of prostate cancer, prostate surgery or 5α-reductase inhibitor treatment of known prostate conditions. The severity of LUTS was assessed using the International Prostate Symptom Score (IPSS). Potential factors associated with LUTS including age, ethnicity, education, history of hypertension, diabetes and hypercholesterolemia, height, weight, and prostate volume were evaluated using univariable and multivariable analyses.

Results

There were 506 (50%) men found to have moderate-to-severe LUTS attaining an IPSS above 7. Overall, nocturia (45.5%) was the most frequently reported symptom. Multivariable analysis showed that age, ethnicity, prostate volume and history of hypertension and hypercholesterolemia were independent factors associated with severity of LUTS (p < 0.05). Considering individual lower urinary tract symptoms, we found a strong association of storage symptom with history of hypertension and hypercholesterolemia. Malay men were significantly bothered by post micturition symptom compared to their Chinese and Indian counterparts. Stratified analyses of LUTS demonstrated a mutually exclusive cardiovascular risk factors profile defined by ethnicity.

Conclusion

Severity of LUTS varies between different ethnicities across all age groups. In addition to age and prostate volume, ethnicity and cardiovascular risk factors including hypertension and hypercholesterolemia may also need to be taken into account in managing men with LUTS.  相似文献   

19.
The aim of this study was to investigate the environmental impact and the human health risks associated with metals exposure in the Catalan stretch of the Ebro River, Spain. The concentrations of the following elements were determined in soils and tap water: As, Cd, Cr, Cu, Hg, Mn, Ni, and Pb. Carcinogenic and non-carcinogenic risks were separately assessed for adults and children. Relatively low metal concentrations in tap water were found. It indicates that water intake is not a relevant source of metals for human health impact in the area under evaluation. In turn, the levels of metals in soils were similar or less than those found in a number of recent worldwide surveys. The presence of industrial facilities located upstream the Ebro River, including a chloralkali plant, should not mean additional non-carcinogenic risks for the population living in the area. The results of the current study allow us to establish that the concentrations of most carcinogenic elements (with the exception of As) should not mean potential health risks for the local population. However, because of the relatively high levels of geological origin found for As, a continued monitoring of these elements would be desirable.  相似文献   

20.

Background

Recent genome-wide association studies (GWAS) have identified novel loci associated with sudden cardiac death (SCD). Despite this progress, identified DNA variants account for a relatively small portion of overall SCD risk, suggesting that additional loci contributing to SCD susceptibility await discovery. The objective of this study was to identify novel DNA variation associated with SCD in the context of coronary artery disease (CAD).

Methods and Findings

Using the MetaboChip custom array we conducted a case-control association analysis of 119,117 SNPs in 948 SCD cases (with underlying CAD) from the Oregon Sudden Unexpected Death Study (Oregon-SUDS) and 3,050 controls with CAD from the Wellcome Trust Case-Control Consortium (WTCCC). Two newly identified loci were significantly associated with increased risk of SCD after correction for multiple comparisons at: rs6730157 in the RAB3GAP1 gene on chromosome 2 (P = 4.93×10−12, OR = 1.60) and rs2077316 in the ZNF365 gene on chromosome 10 (P = 3.64×10−8, OR = 2.41).

Conclusions

Our findings suggest that RAB3GAP1 and ZNF365 are relevant candidate genes for SCD and will contribute to the mechanistic understanding of SCD susceptibility.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号