Biomarkers of Exposure: Arsenic Concentrations in Keratin in Populations Exposed to Arsenic in Drinking Water

<p>Arsenic (As) exposure via groundwater consumption is a global health problem affecting millions. Monitoring exposure is a key step in understanding and predicating future health outcomes. This thesis explores the relationships between arsenic concentrations in toenails and arsenic in water. Three case studies were investigated, with residents from: North Carolina, USA (n=103); the Rift Valley, Ethiopia (n=60); and the Mekong Delta, Vietnam (n=65). Arsenic concentrations above the WHO's recommended 10ppb limit were found in groundwater from the three research sites. </p><p>Arsenic in toenails was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). </p><p>In the Rift Valley of Ethiopia, 53% of the tested drinking wells (n=34) had As above the WHO's limit. Arsenic concentrations in toenails (n=60) were significantly correlated to As concentrations in groundwater (r=0.72; p<0.001), reflecting the direct exposure of rural communities to As in well water, which is their principle water source. Male minors (<18 years old) were found to have greater nail-As concentrations compared with adults consuming equal amounts of As (p<0.05). Estimated As dose specifically from drinking water sources was also associated with nail concentrations (p<0.01). </p><p>In the Mekong Delta of Vietnam (Dong Thap Province), 36 out of the 68 tested wells had As content above the WHO's recommended limit of 10ppb, with levels as high as 981 ppb. Arsenic contents in nails collected from local residents (n=62) were significantly correlated to As in drinking water (r=0.49, p<0.001). Demographic and survey data show that the ratio of As in nail to As in water varies among residents that reflects differential As accumulation in the exposed population. The data show that water filtration and diet, particularly increased consumption of animal protein and dairy and reduced consumption of seafood, were associated with lower ratios of As in nail to As in water and thus could play important roles in mitigating As exposure.</p><p>Sixty-one wells were tested from Union County, North Carolina, with 15 out of 61 wells exceeded the WHO's 10 ppb limit. Arsenic values ranged from below the limit of detection (0.07) to 130ppb, with a mean of 11ppb (median=1.5ppb). Nails were collected from county residents (n=103) and were statistically correlated with As-water concentrations (r=0.48, p<0.001). </p><p>Integration of the data from the three cases studies across different populations and ethnicities show high correlation between As concentrations in groundwater and As in nails in all the three locations (r(Union County)= 0.48, p<0.001; r(Ethiopia)=0.72 p<0.001; r(Vietnam)=0.49, p<0.001). For As-nail to As-water pairs in which As in water was above 1ppb, these three locations are statistically indistinguishable from one another (r=0.62, p<0.001, n=176). These results support the hypothesis that nails can be used as a biomarker of exposure regardless of geographic or ethnic differences in populations considered. Nutrition (meat, seafood, and milk consumption) rather than gender, ethnicity, or dose is suggested to be the major confounding issue affecting the magnitude of As exposure in the human body.</p>Dissertatio

Outcomes and Their State-level Variation in Patients Undergoing Surgery With Perioperative SARS-CoV-2 Infection in the USA. A Prospective Multicenter Study

Objective: To report the 30-day outcomes of patients with perioperative SARS-CoV-2 infection undergoing surgery in the USA. Background: Uncertainty regarding the postoperative risks of patients with SARS-CoV-2 exists. Methods: As part of the COVIDSurg multicenter study, all patients aged ≥17 years undergoing surgery between January 1 and June 30, 2020 with perioperative SARS-CoV-2 infection in 70 hospitals across 27 states were included. The primary outcomes were 30-day mortality and pulmonary complications. Multivariable analyses (adjusting for demographics, comorbidities, and procedure characteristics) were performed to identify predictors of mortality. Results: A total of 1581 patients were included; more than half of them were males (n = 822, 52.0%) and older than 50 years (n = 835, 52.8%). Most procedures (n = 1261, 79.8%) were emergent, and laparotomies (n = 538, 34.1%). The mortality and pulmonary complication rates were 11.0 and 39.5%, respectively. Independent predictors of mortality included age ≥70 years (odds ratio 2.46, 95% confidence interval [1.65-3.69]), male sex (2.26 [1.53-3.35]), ASA grades 3-5 (3.08 [1.60-5.95]), emergent surgery (2.44 [1.31-4.54]), malignancy (2.97 [1.58-5.57]), respiratory comorbidities (2.08 [1.30-3.32]), and higher Revised Cardiac Risk Index (1.20 [1.02-1.41]). While statewide elective cancelation orders were not associated with a lower mortality, a sub-analysis showed it to be associated with lower mortality in those who underwent elective surgery (0.14 [0.03-0.61]). Conclusions: Patients with perioperative SARS-CoV-2 infection have a significantly high risk for postoperative complications, especially elderly males. Postponing elective surgery and adopting non-operative management, when reasonable, should be considered in the USA during the pandemic peaks

Is perioperative COVID-19 really associated with worse surgical outcomes? A nationwide COVIDSurg propensity-matched analysis

BACKGROUND: Patients undergoing surgery with perioperative COVID-19 are suggested to have worse outcomes, but whether this is COVID-related or due to selection bias remains unclear. We aimed to compare the postoperative outcomes of patients with and without perioperative COVID-19. METHODS: Patients with perioperative COVID-19 diagnosed within 7 days before or 30 days after surgery between February and July 2020 from 68 US hospitals in COVIDSurg, an international multicenter database, were 1:1 propensity score matched to patients without COVID-19 undergoing similar procedures in the 2012 American College of Surgeons National Surgical Quality Improvement Program database. The matching criteria included demographics (e.g., age, sex), comorbidities (e.g., diabetes, chronic obstructive pulmonary disease, chronic kidney disease), and operation characteristics (e.g., type, urgency, complexity). The primary outcome was 30-day hospital mortality. Secondary outcomes included hospital length of stay and 13 postoperative complications (e.g., pneumonia, renal failure, surgical site infection). RESULTS: A total of 97,936 patients were included, 1,054 with and 96,882 without COVID-19. Prematching, COVID-19 patients more often underwent emergency surgery (76.1% vs. 10.3%, p &lt; 0.001). A total of 843 COVID-19 and 843 non-COVID-19 patients were successfully matched based on demographics, comorbidities, and operative characteristics. Postmatching, COVID-19 patients had a higher mortality (12.0% vs. 8.1%, p = 0.007), longer length of stay (6 [2-15] vs. 5 [1-12] days), and higher rates of acute renal failure (19.3% vs. 3.0%, p &lt; 0.001), sepsis (13.5% vs. 9.0%, p = 0.003), and septic shock (11.8% vs. 6.0%, p &lt; 0.001). They also had higher rates of thromboembolic complications such as deep vein thrombosis (4.4% vs. 1.5%, p &lt; 0.001) and pulmonary embolism (2.5% vs. 0.4%, p &lt; 0.001) but lower rates of bleeding (11.6% vs. 26.1%, p &lt; 0.001). CONCLUSION: Patients undergoing surgery with perioperative COVID-19 have higher rates of 30-day mortality and postoperative complications, especially thromboembolic, compared with similar patients without COVID-19 undergoing similar surgeries. Such information is crucial for the complex surgical decision making and counseling of these patients. (J Trauma Acute Care Surg. 2023;94: 513-524. Copyright (C) 2023 American Association for the Surgery of Trauma.)LEVEL OF EVIDENCE: Prognostic and Epidemiologic; Level IV