Social ecological system framework as a decision-making tool for risk mitigation: A superfund site case study.

Several studies have reported vapor intrusion (VI) occurring when volatile organic compound (VOC) vapors are transported through subsurface piping systems into building spaces (e.g. conduit VI). Site-specific risk assessment and risk management practices are complicated and evolving for conduit VI, especially at large hazardous waste sites, like Superfund sites, where many stakeholders are involved and have varied interests. Here, we propose a social ecological system (SES) framework as a decision-making tool to inform risk mitigation decisions. We demonstrate the SES framework using field data associated with a Superfund site near San Francisco, California. We evaluate sewer invert elevation and groundwater elevation data, as well as pre- and post- mitigation VOC concentration data within a sewer system. Unexpectedly, the sewer located above the groundwater table was determined to be a potential source of conduit VI risks. The SES framework describes how typical stakeholders associated with the site can affect and be affected by mitigation activities. It informs decisions about mitigation implementation and long-term operation efficacy by considering stakeholder roles and interests. Ultimately, gas siphons were selected as the mitigation technology for the example site. To date, approximately 6 gas siphons have been installed to mitigate conduit VI risks throughout the community. Collectively, our findings advance risk management decisions and highlight key considerations for risk mitigation approaches at hazardous waste sites, including Superfund sites, especially where VI risks are a concern.

A geospatial and binomial logistic regression model to prioritize sampling for per- and polyfluorinated alkyl substances in public water systems.

As health-based drinking water standards for per- and polyfluorinated alkyl substances (PFAS) continue to evolve, public health and environmental protection decision-makers must assess exposure risks associated with all public drinking water systems in the United States (US). Unfortunately, current knowledge regarding the presence of PFAS in environmental systems is limited. In this study, a screening approach was established to: (1) identify and direct attention toward potential PFAS hot spots in drinking water sources, (2) prioritize sampling locations, and (3) provide insights regarding the potential PFAS sources that contaminate groundwater and surface water. Our approach incorporates geospatial data from public sources, including the US Environmental Protection Agency's Toxic Release Inventory, to identify locations where PFAS may be present in drinking water sources. An indicator factor (also known as "risk factor") was developed as a function of distance between potential past and/or present PFAS users (e.g., military bases, industrial sites, and airports) and the public water system, which generates a heat map that visualizes potential exposure risks. A binomial logistic regression model indicates whether PFAS are likely to be detected in public water systems. The results obtained using the developed screening approach aligned well (with a 76% overall model accuracy) with PFAS sampling and chemical analysis data from 81 public drinking water systems in the state of Kentucky. This study proposes this screening model as an effective decision aid to assist key decision-makers in identifying and prioritizing sampling locations for potential PFAS exposure risks in the public drinking water sources in their service areas. Integr Environ Assess Manag 2023;19:163-174. © 2022 SETAC.

MODELING FATE AND TRANSPORT OF VOLATILE ORGANIC COMPOUNDS (VOCs) INSIDE SEWER SYSTEMS.

Hazardous waste site investigations have shown that volatile organic compounds (VOCs) can be transported via sewer pipes and migrate into indoor spaces. Despite field data confirming the presence of this exposure pathway, there is lack of context-based numerical models that provide guidance to characterize and predict VOCs concentration in sewer gas at vapor intrusion sites. Particularly, this poses a challenge when assessing and mitigating risks associated with these exposure pathways. Therefore, a numerical model has been developed to simulate the concentration of VOCs in sewer gas in different stages throughout the sewer lines. The developed model considers various input parameters, including temperature, sewer liquid depth, groundwater depth, and sewer construction characteristics to incorporate local and operational conditions. The model's output is verified using field data from a sewer system constructed near a Superfund site. Moreover, a sensitivity analysis was conducted to evaluate the model's response to variation of the external input parameters. To the best of our knowledge, this study is the first attempt to model VOCs concentration in sewer gas, particularly to address vapor intrusion. The developed model can be used as a numerical tool to support the development of sewer assessment guidelines, risk assessment studies, and mitigation strategies.

Systemic sclerosis: comparison of efficacy of oral cyclophosphamide and azathioprine on skin score and pulmonary involvement-a retrospective study.

The aim of this study was to evaluate efficacy of azathioprine (AZA) and cyclophosphamide (CYC) as a therapeutic regimen for interstitial lung disease associated with systemic sclerosis (SSc). Thirty-six selected patients included in this retrospective cohort and received one of the two drugs; the first group consists of 15 patients who were treated with AZA (1.5-2 mg/kg/day) and the second group with 21 patients received oral CYC (up to 2 mg/kg/day). Both groups received additional low dose of prednisolone (≤10 mg) for 6 months. Forced vital capacity (FVC), diffusion lung capacity for carbon monoxide (DLCO) and skin score were assessed as outcome measures. Modified Rodnan skin score (mRSS), pulmonary function test and DLCO were evaluated at entry and at the end of study after 12 months. The mean (SD) FVC percentages obtained at baseline and post-treatment in AZA-treated patients were 62.8 ± 9.8 and 71.1 ± 20.9 with mean difference of FVC% +7.6 ± 13.1, p = 0.05, and in CYC-treated patients 59.5 ± 10.7, 63.1 ± 16.2 and +2.9 ± 11.5, respectively, p = 0.19. Baseline and post-treatment DLCO% in AZA-treated patients were 61.4 ± 25.8 and 76.7 ± 24.0 with mean difference of +15.0 ± 14.5, respectively, p = 0.01. In CYC-treated patients, those measures were 67.7 ± 27.5 and 60.0 ± 22.9 with mean difference of -8.0 ± 23.7 (p = 0.12). Following 12 months of treatment in AZA-treated patients, mean difference of changes in mRSS was -2.9 ± 3.7 and -1.4 ± 4.5 in CYC-treated patients. Our results indicated that AZA can be effective in ameliorating or stabilizing lung function in selected SSc patient groups.

Alteration of pulmonary function in diabetic nephropathy.

BACKGROUND: Type 2 diabetes mellitus is increasing worldwide with an alarming rate. It is associated with the development of various chronic complications. The aim of this study was to explore the alteration of pulmonary function, and its association with renal complications in people with type 2 diabetes mellitus. METHODS: This cross-sectional study was conducted on three groups; 40 diabetic subjects without nephropathy (urinary albumin<30 mg/day), 40 subjects with nephropathy (urinary albumin≥30 mg/day), and 40 healthy subjects as the control group. The subjects with nephropathy were divided into those with microalbuminuria (urinary albumin=30-300 mg/day) and those with macroalbuminuria (urinary albumin>300 mg/day) .Diabetic subjects were matched to the control group in terms of age, sex, and BMI. Pulmonary function tests were performed and the results were compared between groups. RESULTS: Forced vital capacity (FVC; % predicted), forced expiratory volume in 1 second (FEV1; % predicted), and peak expiratory flow (PEF; % predicted) were significantly lower in subjects with diabetic nephropathy compared to the healthy controls (P<0.05). Meanwhile, in diabetic subjects, FVC and FEV1 were lower in those with diabetic nephropathy compared to those with normal albumin excretion (P<0.05). On the other hand, FEV1/FVC was significantly higher in diabetic people with nephropathy.Furthermore, a significant difference was observed between FVC and FEV1 in diabetic people with microalbuminuria compared to those with macroalbuminuria. CONCLUSIONS: This study showed that the pulmonary function was impaired in people with Diabetes. The progression of diabetic nephropathy to more advanced stages was also associated with more impairment of pulmonary function.

Inhalational exposure to dimethyl sulfate vapor followed by reactive airway dysfunction syndrome.

Dimethyl sulfate (DMS) is an oily liquid used as a solvent, stabilizer, sulfonation agent, and catalyst. Exposure to DMS primarily happens in the workplace via inhalational contact and damages the upper and lower airways. Our manuscript reports a case of DMS-related reactive airway dysfunction syndrome (RADS). The patient was a healthy 29-year-old man who was referred to our ER after accidental exposure to the vapor of DMS with the complaint of dyspnea, dry cough, photophobia, and hoarseness. His vital signs were normal except for a low-grade fever. Redness of the pharynx, conjunctivitis, and cholinergic signs and symptoms were present. Conservative management with O(2) and fluid therapy was initiated. Twenty hours later, the patient became drowsy and his respiratory symptoms exacerbated; chest X-ray revealed haziness in the base of the right lung and prominence of the vessels of the lung hillum. After 1 week, the liver transaminases rose and C-reactive protein elevated (2+). The patient got better with conservative treatment and was discharged after 9 days; however, exertional dyspnea, wheezing, and thick white sputum persisted and therefore, reactive airway dysfunction syndrome (RADS) related to DMS vapor was confirmed which was treated by prednisolone. Exertional dyspnea continued up to 10 months. Hoarseness lasted for 6 months. This case shows that DMS vapor inhalation can cause RADS especially in the chemical workers who continue working in the contaminated place despite the relatively good air conditioning.