Comparison of Trace Organic Chemical Removal Efficiencies between Aerobic and Anaerobic Membrane Bioreactors Treating Municipal Wastewater.

Evaluating persistent trace organic chemicals (TOrCs) and transformation products (TPs) in membrane bioreactors (MBRs) is essential, given that MBRs are now widely implemented for wastewater treatment and water reuse. This research applied comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS)-based nontargeted analysis to compare the effectiveness of parallel aerobic and anaerobic MBRs (AeMBRs and AnMBRs, respectively), treating the same municipal wastewater. The average total chromatographic feature peak area abundances were significantly reduced by 84% and 72% from influent to membrane permeate in both the AeMBR and AnMBR (p < 0.05), respectively. However, the reduction of the average number of chromatographic features was significant for only AeMBR treatment (p = 0.006). A similar number of TPs were generated during both AeMBR and AnMBR treatments (165 vs 171 compounds, respectively). The overall results suggest that the AeMBR was more effective for reducing the diversity of TOrCs than the AnMBR, but both aerobic and anaerobic processes had a similar reduction of TOrC abundance. Suspect screening analysis using GC×GC/TOF-MS, which resulted in the tentative identification of 351 TOrCs, proved to be a powerful approach for uncovering compounds previously unreported in wastewater, including many fragrances and personal care products.

Red Blood Cell Polyunsaturated Fatty Acids and Mortality Following Breast Cancer.

BACKGROUND: Intake of polyunsaturated fatty acids (PUFAs) may impact mortality following breast cancer (BC); however, epidemiological studies have relied on self-reported assessment of PUFA intake. Herein, we examined the associations between red blood cell (RBC) PUFAs and mortality. METHODS: This nested case-control study included 1,104 women from, the Women's Healthy Eating and Living Study, a multi-site randomized controlled trial. Cases (n=290) were women who died from 1995-2006. Matched controls (n=814) were women who were alive at the end of follow-up. PUFAs were measured in baseline RBC samples and included four ω-3 and seven ω-6 PUFAs. We examined each PUFA individually and Principal Components Factor Analysis (PCFA)-derived scores in association with all-cause mortality (ACM) and BC-specific mortality (BCM) using conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: In fully-adjusted models, ACM ORs were elevated among women with PUFAs >median (versus ≤median) for α-linolenic acid (ALA, OR=1.63, 95%CI=1.18-2.24) and for linolenic acid (LA, OR=1.56, 95%CI=1.16-2.09), and BCM ORs were elevated for ALA (OR=1.83, 95%CI=1.27-2.63), LA (OR=1.70, 95%CI=1.23-2.37), and γ-linolenic acid (GLA, OR=1.50; 95%CI=1.04-2.16). PCFA-Factor 1 [arachidonic acid/adrenic acid/docosapentaenoic acid] scores >median (versus ≤median) were associated with lower odds of ACM (OR=0.71; 95%CI=0.52-0.97) and BCM (OR=0.69; 95%CI=0.49-0.97), and PCFA-Factor 4 [ALA/GLA] scores >median (versus ≤median) were associated with increased odds of BCM (OR=1.47; 95%CI=1.04-2.09). CONCLUSIONS: RBC ALA, LA, and GLA may be prognostic indicators among BC survivors. IMPACT: These results are important for understanding the associations between a biomarker of PUFA intake and mortality among BC survivors.

Novel chemical contaminants associated with thirdhand smoke in settled house dust.

Thirdhand smoke (THS) is the persistent and toxic residue from tobacco smoke in indoor environments. A comprehensive understanding of the chemical constituents of THS is necessary to assess the risks of long-term exposure and to establish reliable THS tracers. The objective of this study was to investigate compounds associated with THS through nontargeted analysis (NTA) of settled house dust samples from smokers' and non-smokers' homes, using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS). Compounds that were either only present in dust from smokers' homes or that had significantly larger abundance than in non-smokers' homes were termed qualified compounds. We identified 140 qualified compounds, and of these, 42 compounds were tentatively identified by searching matching mass spectra in NIST electron impact (EI) mass spectral library including 20 compounds confirmed with their authentic standards. Among the 42 compounds, 26 compounds were statistically more abundant (p < 0.10) in dust from homes of smokers; seven were tobacco-specific compounds, two of which (nornicotyrine, 3-ethenylpyridine) have not been reported before in house dust. Two compounds, tris (2-chloroethyl) phosphate (a toxic compound used as a flame retardant and reported in tobacco) and propanoic acid, 2-methyl-, 1-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl ester (highly abundant and reported in exhaled air of smokers), were found in dust from all smokers' homes and in zero non-smokers' homes, making these potential THS tracers, possibly associated with recent smoking. Benzyl methyl ketone was significantly higher in dust in smokers' homes, and was previously reported not as a product of tobacco but rather as a form of methamphetamine. This compound was recently reported in mainstream tobacco smoke condensate through NTA as well. These identified potential tracers and chemical components of THS in this study can be further investigated for use in developing THS contamination and exposure assessments.

Influence of tobacco product wastes in a protected coastal reserve adjacent to urbanization.

The present study, conducted at the Kendall-Frost Mission Bay Marsh Reserve in San Diego, California, aimed to assess tobacco-related pollutants in urban waters, a topic with limited prior research. Across 26 events occurring between November 2019 and February 2022, encompassing both wet and dry seasons at two outfall sites (Noyes St. and Olney St.), water and sediment samples were subjected to analysis for nicotine and cotinine levels, with Noyes St. displaying wide variation in nicotine concentrations, reaching a peak of 50.75 ng/L in water samples, whereas Olney St. recorded a peak of 1.46 ng/L. Wet seasons consistently had higher nicotine levels in water, suggesting the possibility of tobacco litter entering the reserve through stormwater runoff. Cotinine was detected in both sites in both water and sediment samples; however, these levels were considerably lower in comparison to nicotine concentrations. Limited research assesses aquatic environmental pollution from tobacco use and disposal, especially in protected areas like urban natural reserves. This study was conducted at the Kendall-Frost Mission Bay Marsh Reserve in San Diego, California, to evaluate tobacco-related pollutants in San Diego's urban waters. Twenty-six sampling events between November 2019 and February 2022, spanning wet and dry seasons at two outfall sites, were conducted. Nicotine and cotinine, a major ingredient of tobacco and its metabolite, were analyzed in the collected water and sediment samples. Nicotine concentrations differed substantially between the outfall locations (Noyes St. and Olney St.), with Noyes St. displaying wide variations, averaging at 9.31 (±13.24) ng/L with a maximum concentration of 50.75 ng/L, and Olney St. at 0.53 (±0.41) ng/L with a maximum concentration of 1.46 ng/L in water samples. In both locations, the nicotine concentrations in water samples were higher during wet seasons than dry seasons, and this pattern was more significant at Noyes St. outfall than at Olney St. outfall, which received not only stormwater runoff but also was connected to Mission Bay. Although this pattern did not directly align with sediment nicotine levels at both sites, maximum nicotine concentration in Noyes St. sediments during wet seasons was approximately 120 times higher than in Olney St. sediments. Regarding cotinine, Noyes St. outfall water averaged 3.17 ng/L (±1.88), and Olney St. water averaged 1.09 ng/L (±1.06). Similar to nicotine, the cotinine concentrations were higher in Noyes St. water and sediment compared to Olney St., but overall, the cotinine concentrations in both water and sediment were much lower than the corresponding nicotine concentrations. The study identifies urban stormwater runoff as a potential source of nicotine and cotinine pollution in a protected reserve, implicating tobacco product litter and human tobacco use as contributing factors.

Contamination of surfaces in children's homes with nicotine and the potent carcinogenic tobacco-specific nitrosamine NNK.

BACKGROUND: Tobacco smoke exposure (TSE) through secondhand and thirdhand smoke is a modifiable risk factor that contributes to childhood morbidity. Limited research has assessed surface TSE pollution in children's environments as a potential source of thirdhand smoke exposure, and none have examined levels of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on surfaces. OBJECTIVE: This study measured surface NNK and nicotine in children's homes and associations with sociodemographics and parent-reported TSE behaviors. We assessed correlations of surface NNK and nicotine with dust NNK, dust nicotine, and child cotinine. METHODS: Home surface wipe NNK and nicotine data from 84 children who lived with smokers were analyzed. Tobit and simple linear regression analyses were conducted to assess associations of surface NNK and nicotine with child characteristics. Spearman's (ρ) correlations assessed the strength of associations between environmental markers and child cotinine. RESULTS: Nearly half (48.8%) of children's home surfaces had detectable NNK and 100% had detectable nicotine. The respective geometric means (GMs) of surface NNK and nicotine loadings were 14.0 ng/m2 and 16.4 µg/m2. Surface NNK positively correlated with surface nicotine (ρ = 0.54, p < 0.001) and dust NNK (ρ = 0.30, p = 0.020). Surface nicotine positively correlated with dust NNK (ρ = 0.42, p < 0.001) and dust nicotine (ρ = 0.24, p = 0.041). Children with household incomes ≤$15,000 had higher surface NNK levels (GM = 18.7 ng/m2, p = 0.017) compared to children with household incomes >$15,000 (GM = 7.1 ng/m2). Children with no home smoking bans had higher surface NNK (GM = 18.1 ng/m2, p = 0.020) and surface nicotine (GM = 17.7 µg/m2, p = 0.019) levels compared to children with smoking bans (GM = 7.5 ng/m2, 4.8 µg/m2, respectively). IMPACT: Although nicotine on surfaces is an established marker of thirdhand smoke pollution, other thirdhand smoke contaminants have not been measured on surfaces in the homes of children living with smokers. We provide evidence that the potent carcinogenic tobacco-specific nitrosamine NNK was detectable on surfaces in nearly half of children's homes, and nicotine was detectable on all surfaces. Surface NNK was positively correlated with surface nicotine and dust NNK. Detectable surface NNK levels were found in homes with indoor smoking bans, indicating the role of NNK as a persistent thirdhand smoke pollutant accumulating on surfaces as well as in dust.

Changes and stability of hand nicotine levels in children of smokers: Associations with urinary biomarkers, reported child tobacco smoke exposure, and home smoking bans.

BACKGROUND: Exposure to thirdhand smoke (THS) residue takes place through inhalation, ingestion, and dermal transfer. Hand nicotine levels have been proposed to measure THS pollution in the environment of children, but little is known about its variability and stability over time and correlates of change. OBJECTIVES: The goal was to determine the stability of hand nicotine in comparison to urinary biomarkers and to explore factors that influence changes in hand nicotine. METHODS: Data were collected from 0 to 11-year-old children (Mean age = 5.9) who lived with ≥1 tobacco smokers (N = 129). At a 6-week interval, we collected repeated measures of hand nicotine, four urinary biomarkers (cotinine, trans-3'-hydroxycotinine, nicotelline N-oxides, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), and parent-reported child tobacco smoke exposure (TSE). Dependent sample t-tests, correlations, and multivariable regression analyses were conducted to examine the changes in child TSE. RESULTS: Hand nicotine levels (r = 0.63, p < 0.001) showed similar correlations between repeated measures to urinary biomarkers (r = 0.58-0.71; p < 0.001). Different from urinary biomarkers, mean hand nicotine levels increased over time (t(113) = 3.37, p < 0.001) being significantly higher in children from homes without smoking bans at Time 2 (p = 0.016) compared to Time 1 (p = 0.003). Changes in hand nicotine correlated with changes in cotinine and trans-3'-hydroxycotinine (r = 0.30 and r = 0.19, respectively, p < 0.05). Children with home smoking bans at Time 1 and 2 showed significantly lower hand nicotine levels compared to children without home smoking bans. DISCUSSION: Findings indicate that hand nicotine levels provide additional insights into children's exposure to tobacco smoke pollutants than reported child TSE and urinary biomarkers. Changes in hand nicotine levels show that consistent home smoking bans in homes of children of smokers can lower THS exposure. Hand nicotine levels may be influenced by the environmental settings in which they are collected.

Leached Compounds from Smoked Cigarettes and Their Potential for Bioaccumulation in Rainbow Trout (Oncorhynchus mykiss).

Cigarette butts are one of the most prevalent forms of litter worldwide and may leach toxic compounds when deposited in aquatic environments. Previous studies demonstrated that smoked cigarette leachate is toxic toward aquatic organisms. However, the specific bioavailable chemicals from the leachate and the potential for human and wildlife exposure through the food chain were unknown. Using a nontargeted analytical approach based on GC×GC/TOF-MS, 43 compounds were confirmed to leach from smoked cigarettes when exposed to a water source. Additionally, the bioaccumulation potential of organic contaminants in an edible fish, rainbow trout (Oncorhynchus mykiss), was assessed through direct exposure to the leachate of smoked cigarettes at 0.5 CB/L for 28 days. There was a significant reduction in fish mass among the exposed rainbow trout vs the control group (χ2 (1) = 5.3, p = 0.021). Both nontargeted and targeted chemical analysis of representative fish tissue identified four tobacco alkaloids, nicotine, nicotyrine, myosmine, and 2,2'-bipyridine. Their average tissue concentrations were 466, 55.4, 94.1, and 70.8 ng/g, respectively. This study identifies leached compounds from smoked cigarettes and demonstrates the uptake of specific chemicals in rainbow trout, thus suggesting a potential for accumulation in food webs, resulting in human and wildlife exposure.

Policy-relevant differences between secondhand and thirdhand smoke: strengthening protections from involuntary exposure to tobacco smoke pollutants.

Starting in the 1970s, individuals, businesses and the public have increasingly benefited from policies prohibiting smoking indoors, saving thousands of lives and billions of dollars in healthcare expenditures. Smokefree policies to protect against secondhand smoke exposure, however, do not fully protect the public from the persistent and toxic chemical residues from tobacco smoke (also known as thirdhand smoke) that linger in indoor environments for years after smoking stops. Nor do these policies address the economic costs that individuals, businesses and the public bear in their attempts to remediate this toxic residue. We discuss policy-relevant differences between secondhand smoke and thirdhand smoke exposure: persistent pollutant reservoirs, pollutant transport, routes of exposure, the time gap between initial cause and effect, and remediation and disposal. We examine four policy considerations to better protect the public from involuntary exposure to tobacco smoke pollutants from all sources. We call for (a) redefining smokefree as free of tobacco smoke pollutants from secondhand and thirdhand smoke; (b) eliminating exemptions to comprehensive smoking bans; (c) identifying indoor environments with significant thirdhand smoke reservoirs; and (d) remediating thirdhand smoke. We use the case of California as an example of how secondhand smoke-protective laws may be strengthened to encompass thirdhand smoke protections. The health risks and economic costs of thirdhand smoke require that smokefree policies, environmental protections, real estate and rental disclosure policies, tenant protections, and consumer protection laws be strengthened to ensure that the public is fully protected from and informed about the risks of thirdhand smoke exposure.

Remediation of Thirdhand Tobacco Smoke with Ozone: Probing Deep Reservoirs in Carpets.

We assessed the efficacy of ozonation as an indoor remediation strategy by evaluating how a carpet serves as a sink and long-term source of thirdhand tobacco smoke (THS) while protecting contaminants absorbed in deep reservoirs by scavenging ozone. Specimens from unused carpet that was exposed to smoke in the lab ("fresh THS") and contaminated carpets retrieved from smokers' homes ("aged THS") were treated with 1000 ppb ozone in bench-scale tests. Nicotine was partially removed from fresh THS specimens by volatilization and oxidation, but it was not significantly eliminated from aged THS samples. By contrast, most of the 24 polycyclic aromatic hydrocarbons detected in both samples were partially removed by ozone. One of the home-aged carpets was installed in an 18 m3 room-sized chamber, where its nicotine emission rate was 950 ng day-1 m-2. In a typical home, such daily emissions could amount to a non-negligible fraction of the nicotine released by smoking one cigarette. The operation of a commercial ozone generator for a total duration of 156 min, reaching concentrations up to 10,000 ppb, did not significantly reduce the carpet nicotine loading (26-122 mg m-2). Ozone reacted primarily with carpet fibers, rather than with THS, leading to short-term emissions of aldehydes and aerosol particles. Hence, by being absorbed deeply into carpet fibers, THS constituents can be partially shielded from ozonation.

Clouding Up Cognition? Secondhand Cannabis and Tobacco Exposure Related to Cognitive Functioning in Youth.

Background: Increasing legalization of cannabis, in addition to longstanding rates of tobacco use, raises concerns for possible cognitive decrements from secondhand smoke or environmental exposure, although little research exists. We investigate the relation between cognition and secondhand and environmental cannabis and tobacco exposure in youth. Methods: The Adolescent Brain Cognitive Development (ABCD) Study year 2 follow-up (N = 5580; 48% female) cognitive performance and secondhand or environmental cannabis or tobacco exposure data were used. Principal components analysis identified a global cognition factor. Linear mixed-effects models assessed global cognition and individual cognitive task performance by cannabis and/or tobacco environmental exposure. Sociodemographics and other potential confounds were examined. p values were adjusted using the false discovery rate method. Results: Global cognition was not related to any exposure group after testing corrections and considering confounds. Beyond covariates and family- and site-level factors, secondhand tobacco was related to poorer visual memory (p = .02), and environmental tobacco was associated with poorer visuospatial (p = .02) and language (p = .008) skills. Secondhand cannabis was related to cognition, but not after controlling for potential confounders (p > .05). Environmental cannabis was related to better oral reading (p = .01). Including covariates attenuated effect sizes. Conclusions: Secondhand tobacco exposure was associated with poorer visual memory, while environmental tobacco exposure was related to poorer language and visuospatial skills. Secondhand cannabis was not related to cognition after controlling for sociodemographic factors, but environmental cannabis exposure was related to better reading. Because, to our knowledge, this is the first known study of its kind and thus preliminary, secondhand cannabis should continue to be investigated to confirm results.

Hand nicotine as an independent marker of thirdhand smoke pollution in children's environments.

BACKGROUND: Hand nicotine (HN) levels measure children's exposure to tobacco smoke pollutants from thirdhand and secondhand smoke. HN is associated with urinary and salivary cotinine, but the associations of HN with other tobacco smoke exposure (TSE) markers remain unknown. OBJECTIVES: We compared levels of HN and four urinary TSE biomarkers: cotinine, trans-3'-hydroxycotinine (3HC), nicotelline N-oxides, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and children's sociodemographic and TSE patterns. We also examined if HN is a plausible pathway for children's exposure to active smoking. METHODS: Data were collected from 175 non-smoking patients (Mean (SD) age = 5.4 (3.4) years) who lived with ≥1 cigarette smoker(s). HN and TSE biomarker levels were determined using LC-MS/MS. Multivariate and multivariable regression analyses were conducted to examine associations between TSE markers and parent-reported measures, controlling for sociodemographics. RESULTS: Of the five markers of TSE, cotinine (R2 = 0.221; p = 0.003) and HN (R2 = 0.247; p = 0.001) showed the strongest overall associations. Of the five markers, only cotinine showed significantly higher levels among Black children (ß^=0.307,p<0.05) independent of age, reported exposure, and home smoking bans. Cotinine (ß^=0.010,p<0.05), NNAL (ß^=0.012,p<0.05), and HN (ß^=0.011,p<0.05) showed significant positive associations with reported exposure independent of race, age, and home smoking bans. NNAL (ß^=-0.285,p<0.05) and HN (ß^=-0.336,p<0.05), but not cotinine, 3HC, and N-oxides, showed significantly lower levels among children who lived in homes with smoking bans. Child age, hand surface area, home smoking ban, and reported exposure independently accounted for 21 % of the variance in HN levels (p = 0.002). HN accounted for 30 % of the variance in cotinine independent of child race and child age. DISCUSSION: HN levels were associated with modifiable tobacco-related behaviors and shows promise as a marker of sources of THS pollution in a child's environment not captured by measurement of urinary cotinine alone. HN levels provide additional information about TSE, complementing other biomarkers when assessing children's overall TSE.

Thirdhand Exposures to Tobacco-Specific Nitrosamines through Inhalation, Dust Ingestion, Dermal Uptake, and Epidermal Chemistry.

Tobacco-specific nitrosamines (TSNAs) are emitted during smoking and form indoors by nitrosation of nicotine. Two of them, N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are human carcinogens with No Significant Risk Levels (NSRLs) of 500 and 14 ng day-1, respectively. Another TSNA, 4-(methylnitrosamino)-4-(3-pyridyl) butanal (NNA), shows genotoxic and mutagenic activity in vitro. Here, we present additional evidence of genotoxicity of NNA, an assessment of TSNA dermal uptake, and predicted exposure risks through different pathways. Dermal uptake was investigated by evaluating the penetration of NNK and nicotine through mice skin. Comparable mouse urine metabolite profiles suggested that both compounds were absorbed and metabolized via similar mechanisms. We then investigated the effects of skin constituents on the reaction of adsorbed nicotine with nitrous acid (epidermal chemistry). Higher TSNA concentrations were formed on cellulose and cotton substrates that were precoated with human skin oils and sweat compared to clean substrates. These results were combined with reported air, dust, and surface concentrations to assess NNK intake. Five different exposure pathways exceeded the NSRL under realistic scenarios, including inhalation, dust ingestion, direct dermal contact, gas-to-skin deposition, and epidermal nitrosation of nicotine. These results illustrate potential long-term health risks for nonsmokers in homes contaminated with thirdhand tobacco smoke.

Assessing Marine Endocrine-Disrupting Chemicals in the Critically Endangered California Condor: Implications for Reintroduction to Coastal Environments.

Coastal reintroduction sites for California condors (Gymnogyps californianus) can lead to elevated halogenated organic compound (HOC) exposure and potential health impacts due to the consumption of scavenged marine mammals. Using nontargeted analysis based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS), we compared HOC profiles of plasma from inland and coastal scavenging California condors from the state of California (CA), and marine mammal blubber from CA and the Gulf of California off Baja California (BC), Mexico. We detected more HOCs in coastal condors (32 ± 5, mean number of HOCs ± SD, n = 7) than in inland condors (8 ± 1, n = 10) and in CA marine mammals (136 ± 87, n = 25) than in BC marine mammals (55 ± 46, n = 8). ∑DDT-related compounds, ∑PCBs, and total tris(chlorophenyl)methane (∑TCPM) were, respectively, ∼7, ∼3.5, and ∼148 times more abundant in CA than in BC marine mammals. The endocrine-disrupting potential of selected polychlorinated biphenyls (PCB) congeners, TCPM, and TCPMOH was determined by in vitro California condor estrogen receptor (ER) activation. The higher levels of HOCs in coastal condors compared to those in inland condors and lower levels of HOC contamination in Baja California marine mammals compared to those from the state of California are factors to consider in condor reintroduction efforts.

A systematic review of the use of silicone wristbands for environmental exposure assessment, with a focus on polycyclic aromatic hydrocarbons (PAHs).

BACKGROUND: Exposure assessment is critical for connecting environmental pollutants to health outcomes and evaluating impacts of interventions or environmental policies. Silicone wristbands (SWBs) show promise for multi-pollutant exposure assessment, including polycyclic aromatic hydrocarbons (PAHs), a ubiquitous class of toxic environmental pollutants. OBJECTIVE: To review published studies where SWBs were worn on the wrist for human environmental exposure assessments and evaluate the ability of SWBs to capture personal exposures, identify gaps which need to be addressed to implement this tool, and make recommendations for future studies to advance the field of exposure science through utilization of SWBs. METHODS: We performed a systematic search and a cited reference search in Scopus and extracted key study descriptions. RESULTS: Thirty-nine unique studies were identified, with analytes including PAHs, pesticides, flame retardants, and tobacco products. SWBs were shipped under ambient conditions without apparent analyte loss, indicating utility for global exposure and health studies. Nineteen articles detected a total of 60 PAHs in at least one SWB. Correlations with other concurrent biological and air measurements indicate the SWB captures exposure to flame retardants, tobacco products, and PAHs. SIGNIFICANCE: SWBs show promise as a simple-to-deploy tool to estimate environmental and occupational exposures to chemical mixtures, including PAHs.

Persistence and removal of trace organic compounds in centralized and decentralized wastewater treatment systems.

The persistence of trace organic chemicals in treated effluent derived from both centralized wastewater treatment plants (WWTPs) and decentralized wastewater treatment systems (DEWATS) is of concern due to their potential impacts on human and ecosystem health. Here, we utilize non-targeted analysis (NTA) with comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC × GC/TOF-MS) to conduct an evaluation of the common persistent and removed compounds found in two centralized WWTPs in the USA and South Africa and one DEWATS in South Africa. Overall, removal efficiencies of chemicals were similar between the treatment plants when they were compared according to the number of chemical features detected in the influents and effluents of each treatment plant. However, the DEWATS treatment train, which has longer solids retention and hydraulic residence times than both of the centralized WWTPs and utilizes primarily anaerobic treatment processes, was able to remove 13 additional compounds and showed a greater decrease in normalized peak areas compared to the centralized WWTPs. Of the 111 common compounds tentatively identified in all three influents, 11 compounds were persistent in all replicates, including 5 compounds not previously reported in effluents of WWTPs or water reuse systems. There were no significant differences among the physico-chemical properties of persistent and removed compounds, but significant differences were observed among some of the molecular descriptors. These results have important implications for the treatment of trace organic chemicals in centralized and decentralized WWTPs and the monitoring of new compounds in WWTP effluent.

Handwashing Results in Incomplete Nicotine Removal from Fingers of Individuals who Smoke: A Randomized Controlled Experiment.

OBJECTIVE: Tobacco residue, also known as third-hand smoke (THS), contains toxicants and lingers in dust and on surfaces and clothes. THS also remains on hands of individuals who smoke, with potential transfer to infants during visitation while infants are hospitalized in neonatal intensive care units (NICUs), raising concerns (e.g., hindered respiratory development) for vulnerable infants. Previously unexplored, this study tested handwashing (HW) and sanitization efficacy for finger-nicotine removal in a sample of adults who smoked and were visiting infants in an NICU. STUDY DESIGN: A cross-sectional sample was recruited to complete an interview, carbon monoxide breath samples, and three nicotine wipes of separate fingers (thumb, index, and middle). Eligible participants (n = 14) reported current smoking (verified with breath samples) and were randomly assigned to 30 seconds of HW (n = 7) or alcohol-based sanitization (n = 7), with the order of finger wipes both counterbalanced and randomly assigned. After randomization, the first finger was wiped for nicotine. Participants then washed or sanitized their hands and finger two was wiped 5 minutes later. An interview assessing tobacco/nicotine use and exposure was then administered, followed by a second breath sample and the final finger wipe (40-60 minutes after washing/sanitizing). RESULTS: Generalized linear mixed models found that HW was more effective than sanitizer for nicotine removal but failed to completely remove nicotine. CONCLUSIONS: Without proper protections (e.g., wearing gloves and gowns), NICU visitors who smoke may inadvertently expose infants to THS. Research on cleaning protocols are needed to protect vulnerable medical populations from THS and associated risks. KEY POINTS: · NICU infants may be exposed to THS via visitors.. · THS is not eliminated by HW or sanitizing.. · THS removal protections for NICU infants are needed..

Automated high confidence compound identification of electron ionization mass spectra for nontargeted analysis.

Nontargeted analysis based on mass spectrometry is a rising practice in environmental monitoring for identifying contaminants of emerging concern. Nontargeted analysis performed using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC/TOF-MS) generates large numbers of possible analytes. Moreover, the default spectral library similarity score-based search algorithm used by LECO® ChromaTOF® does not ensure that high similarity scores result in correct library matches. Therefore, an additional manual screening is necessary, but leads to human errors especially when dealing with large amounts of data. To improve the speed and accuracy of the chemical identification, we developed CINeMA.py (Classification Is Never Manual Again). This programming suite automates GC×GC/TOF-MS data interpretation by determining the confidence of a match between the observed analyte mass spectrum and the LECO® ChromaTOF® software generated library hit from the NIST Electron Ionization Mass Spectral (NIST EI-MS) library. Our script allows the user to evaluate the confidence of the match using an algorithmic method that mimics the manual curation process and two different machine learning approaches (neural networks and random forest). The script allows the user to adjust various parameters (e.g., similarity threshold) and study their effects on prediction accuracy. To test CINeMA.py, we used data from two different environmental contaminant studies: an EPA study on household dust and a study on stormwater runoff. Using a reference set based on the analysis performed by highly trained users of the ChromaTOF and GC×GC/TOF-MS systems, the random forest model had the highest prediction accuracies of 86% and 83% on the EPA and Stormwater data sets, respectively. The algorithmic approach had the second-best prediction accuracy (82% and 79%), while the neural network accuracy had the lowest (63% and 67%). All the approaches required less than 1 min to classify 986 observed analytes, whereas manual data analysis required hours or days to complete. Our methods were also able to detect high confidence matches missed during the manual review. Overall, CINeMA.py provides users with a powerful suite of tools that should significantly speed-up data analysis while reducing the possibilities of manual errors and discrepancies among users, and can be applicable to other GC/EI-MS instrument based nontargeted analysis.

Differential associations of hand nicotine and urinary cotinine with children's exposure to tobacco smoke and clinical outcomes.

BACKGROUND: Children's overall tobacco smoke exposure (TSE) consists of both inhalation of secondhand smoke (SHS) and ingestion, dermal uptake, and inhalation of thirdhand smoke (THS) residue from dust and surfaces in their environments. OBJECTIVES: Our objective was to compare the different roles of urinary cotinine as a biomarker of recent overall TSE and hand nicotine as a marker of children's contact with nicotine pollution in their environments. We explored the differential associations of these markers with sociodemographics, parental smoking, child TSE, and clinical diagnoses. METHODS: Data were collected from 276 pediatric emergency department patients (Median age = 4.0 years) who lived with a cigarette smoker. Children's hand nicotine and urinary cotinine levels were determined using LC-MS/MS. Parents reported tobacco use and child TSE. Medical records were reviewed to assess discharge diagnoses. RESULTS: All children had detectable hand nicotine (GeoM = 89.7ng/wipe; 95 % CI = [78.9; 102.0]) and detectable urinary cotinine (GeoM = 10.4 ng/ml; 95%CI = [8.5; 12.6]). Although hand nicotine and urinary cotinine were highly correlated (r = 0.62, p < 0.001), urinary cotinine geometric means differed between racial groups and were higher for children with lower family income (p < 0.05), unlike hand nicotine. Independent of urinary cotinine, age, race, and ethnicity, children with higher hand nicotine levels were at increased risk to have discharge diagnoses of viral/other infectious illness (aOR = 7.49; 95%CI = [2.06; 27.24], p = 0.002), pulmonary illness (aOR = 6.56; 95%CI = [1.76; 24.43], p = 0.005), and bacterial infection (aOR = 5.45; 95%CI = [1.50; 19.85], p = 0.03). In contrast, urinary cotinine levels showed no associations with diagnosis independent of child hand nicotine levels and demographics. DISCUSSION: The distinct associations of hand nicotine and urinary cotinine suggest the two markers reflect different exposure profiles that contribute differentially to pediatric illness. Because THS in a child's environment directly contributes to hand nicotine, additional studies of children of smokers and nonsmokers are warranted to determine the role of hand nicotine as a marker of THS exposure and its potential role in the development of tobacco-related pediatric illnesses.

Framework for nontargeted investigation of contaminants released by wildfires into stormwater runoff: Case study in the northern San Francisco Bay area.

Wildfires can be extremely destructive to communities and ecosystems. However, the full scope of the ecological damage is often hard to assess, in part due to limited information on the types of chemicals introduced to affected landscapes and waterways. The objective of this study was to establish a sampling, analytical, and interpretive framework to effectively identify and monitor contaminants of emerging concern in environmental water samples impacted by wildfire runoff. A nontargeted analysis consisting of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC/TOF-MS) was conducted on stormwater samples from watersheds in the City of Santa Rosa and Sonoma and Napa Counties, USA, after the three most destructive fires during the October 2017 Northern California firestorm. Chemicals potentially related to wildfires were selected from the thousands of chromatographic features detected through a screening method that compared samples from fire-impacted sites versus unburned reference sites. This screening led to high confidence identifications of 76 potentially fire-related compounds. Authentic standards were available for 48 of these analytes, and 46 were confirmed by matching mass spectra and GC × GC retention times. Of these 46 compounds, 37 had known commercial and industrial uses as intermediates or ingredients in plastics, personal care products, pesticides, and as food additives. Nine compounds had no known uses or sources and may be oxidation products resulting from burning of natural or anthropogenic materials. Preliminary examination of potential toxicity associated with the 46 compounds, conducted via online databases and literature review, indicated limited data availability. Regional comparison suggested that more structural damage may yield a greater number of unique, potentially wildfire-related compounds. We recommend further study of post-wildfire runoff using the framework described here, which includes hypothesis-driven site selection and nontargeted analysis, to uncover potentially significant stormwater contaminants not routinely monitored after wildfires and inform risk assessment. Integr Environ Assess Manag 2021;17:1179-1193. © 2021 SETAC.