Availability Versus Accessibility: Identifying COVID-19 Testing Deserts Across Massachusetts.

Throughout the COVID-19 pandemic, communities of color have faced significantly higher rates of COVID-19 infection, as well as poor clinical outcomes. These differences are driven by long-standing structural inequities that prevent effective social distancing efforts and are further exacerbated by disparities in COVID-19 testing. Our study applied the concept of "COVID-19 testing deserts" to systematically identify gaps in testing resource allocation across Massachusetts in May 2020 and March 2021. Testing deserts were identified at the census tract level, using criteria developed by the Department of Agriculture for food deserts. Testing deserts occurred more frequently in segregated Hispanic, segregated Black, mixed minority, and integrated communities, as well as in neighborhoods with low vehicle access and in federally designated Medically Underserved Areas. Segregated communities were those in which more than 50 percent of the population self-identified as non-Hispanic White, Hispanic, non-Hispanic Black, or non-Hispanic Asian, respectively. Testing deserts were overrepresented in counties with high COVID-19 incidence rates, suggesting that testing accessibility is essential for prompt COVID-19 diagnosis and self-isolation.

Socio-demographic factors associated with hunger among food pantry users in Eastern Massachusetts.

To assess the determinants of hunger among food pantry users, the present study used a cross-sectional survey that included a modified Household Hunger Scale to quantify hunger. Mixed-effects logistic regression models were used to assess the relationship between hunger categories and various household socio-demographic and economic characteristics, such as age, race, household size, marital status and experience of any economic hardship. The survey was administered to food pantry users from June 2018 to August 2018 at various food pantries across Eastern Massachusetts with 611 food pantry users completing the questionnaire at any of the 10 food pantry sites. One-fifth (20⋅13 %) of food pantry users experienced moderate hunger and 19⋅14 % experienced severe hunger. Food pantry users who were single, divorced or separated; had less than a high school education; working part-time, unemployed or retired; or, who earned incomes less than $1000 per month were most likely to experience severe or moderate hunger. Pantry users who experienced any economic hardship had 4⋅78 the adjusted odds of severe hunger (95 % CI 2⋅49, 9⋅19), which was much larger than the odds of moderate hunger (AOR 1⋅95; 95 % CI 1⋅10, 3⋅48). Younger age and participation in WIC (AOR 0⋅20; 95 % CI 0⋅05-0⋅78) and SNAP (AOR 0⋅53; 95 % CI 0⋅32-0⋅88) were protective against severe hunger. The present study illustrates factors affecting hunger in food pantry users, which can help inform public health programmes and policies for people in need of additional resources. This is essential particularly in times of increasing economic hardships recently exacerbated by the COVID-19 pandemic.

Improving front-line clinician capacity to address depression and bipolar disorder among perinatal individuals: a longitudinal analysis of the Massachusetts Child Psychiatry Access Program (MCPAP) for Moms.

Perinatal mood disorders (PMDs) are common, yet many patients are undertreated. The Massachusetts Child Psychiatry Access Program (MCPAP) for Moms is designed to increase clinicians' willingness to address PMDs. We examined utilization of MCPAP for Moms and associations with PMDs treatment, including the more complex bipolar disorder (BD). Analyses of MCPAP for Moms data examined utilization from 7/2014 to 6/2020 and associated treatment outcomes. Participants were clinicians (n = 1006) in obstetrics/gynecology, family medicine, and pediatrics. Encounters included (1) resource and referrals and (2) psychiatric consultations (program psychiatrist consultation with clinicians or patients). Utilization sub-groups were identified using group-based trajectory modeling. Higher utilization of MCPAP for Moms was associated with increased rates of treating PMDs (incidence rate ratio [IRR] = 1.07, 95% CI: 1.06-1.07). Examining by encounter type, psychiatric consultations resulted in more frequent rates of clinicians treating PMDs than resource and referral encounters. Utilization of direct patient consultation was associated with the greatest increase in rates of clinicians treating BD (IRR = 2.12, 95% CI: 1.82-2.41). Clinicians with highest utilization rates of psychiatric consultations longitudinally had strongest predictive associations with providing direct mental healthcare to patients with BD (IRR = 13.5, 95% CI: 4.2-43.2). Utilization of MCPAP for Moms facilitates clinicians' ability to provide mental health treatment to patients.

Assessment of a Price Index for Hospital Outpatient Department Services Using Commercial Claims Data in Massachusetts.

This cross-sectional study assesses a market basket price index to evaluate hospital outpatient department price levels and growth.

Perspectives of opioid prescribers in overdose hotspots and coldspots, Massachusetts, 2019.

BACKGROUND: Prescription opioids (POs) have had a devastating effect on people and public health systems in the U.S. Due to the urgency and complexity of the opioid crisis, there is a need to expand qualitative research on the medical community's perspectives on opioid prescribing practices and the role that prescription drug monitoring programs (PDMPs) have played in mitigating this crisis. METHODS: We conducted qualitative interviews with clinicians (n = 23) across specialties and a range of overdose hotspot and coldspot locations in Massachusetts during 2019. We aimed to capture their perspectives on the opioid crisis, changes in clinical practice, and experiences with opioid prescribing and PDMPs. RESULTS: Respondents consistently recognized the role clinicians played in the opioid crisis and reported reductions in their opioid prescribing, which were motivated by the crisis itself. The limitations of opioids in pain management were frequently discussed. While clinicians appreciated having greater awareness of their opioid prescribing and increased access to patient prescription histories, they also expressed concerns about surveillance of their prescribing and other unintended consequences. We observed that clinicians in opioid prescribing hotspots had more detailed and specific reflections on their experiences with the Massachusetts PDMP, MassPAT. CONCLUSION: Clinician perceptions of the severity of the opioid crisis in Massachusetts and thoughts on their role as prescribers were consistent across specialty, prescribing level, and practice location. Many clinicians in our sample cited use of the PDMP as an influence on their prescribing. Those practicing in opioid overdose hotspots had the most nuanced reflections about the system.

Group Home Staff Experiences With Work and Health in the COVID-19 Pandemic in Massachusetts.

Importance: Direct reports of the experiences of staff working in group homes for people with serious mental illness (SMI) and/or intellectual or developmental disabilities (ID/DD) are rarely reported. Hearing from workers about their experiences in the COVID-19 pandemic may inform future workforce and public policy. Objective: To gather baseline data on worker experience with the perceived effects of COVID-19 on health and work in the pandemic prior to initiating an intervention to mitigate the spread of COVID-19 and to measure differences in worker experience by gender, race, ethnicity, education, and resident population served (persons with SMI and/or IDD/DD). Design, Setting, and Participants: This mixed-mode, cross-sectional survey study was conducted using online then paper-based self-administration from May to September 2021 at the end of the first year of the pandemic. Staff working in 415 group homes that provided care within 6 Massachusetts organizations serving adults aged 18 years or older with SMI and/or ID/DD were surveyed. The eligible survey population included a census of staff who were currently employed in participating group homes during the study period. A total of 1468 staff completed or partially completed surveys. The overall survey response rate was 44% (range by organization, 20% to 52%). Main Outcomes and Measures: Self-reported experiential outcomes were measured in work, health, and vaccine completion. Bivariate and multivariate analyses explore experiences by gender, race, ethnicity, education, trust in experts and employers, and population served. Results: The study population included 1468 group home staff (864 [58.9%] women; 818 [55.7%] non-Hispanic Black; 98 [6.7%] Hispanic or Latino). A total of 331 (22.5%) group home staff members reported very serious perceived effects on health; 438 (29.8%) reported very serious perceived effects on mental health; 471 (32.1%) reported very serious perceived effects on health of family and friends; and 414 reported very serious perceived effects (28.2%) on access to health services, with statistically significant differences observed by race and ethnicity. Vaccine acceptance was higher among persons with higher educational attainment and trust in scientific expertise and lower among persons who self-reported as Black or Hispanic/Latino. A total of 392 (26.7%) respondents reported needing support for health needs, and 290 (19.8%) respondents reported needing support for loneliness or isolation. Conclusions and Relevance: In this survey study, approximately one-third of group home workers reported serious personal health and access to health care barriers during the first year of the COVID-19 pandemic in Massachusetts. Addressing unmet health needs and access to health and mental health services, including inequities and disparities by race, ethnicity, and education, should benefit staff health and safety, as well as that of the individuals with disabilities who rely on them for support and care.

Severity of COVID-19-Related Illness in Massachusetts, July 2021 to December 2022.

This cohort study uses hospitalization and 30-day mortality risks to create a temporal profile of the severity of COVID-19 in Massachusetts from July 2021 to December 2022.

Evidence of Uranotaenia sapphirina (Diptera: Culicidae) feeding on annelid worms in the Northeastern United States.

Mosquito host-feeding behavior is an important parameter for determining the vector potential of mosquito species in a given locale. Despite the recent discovery of Uranotaenia sapphirina Osten Sacken feeding on annelid hosts in Florida, host association studies for this mosquito species in the United States remain limited. To investigate the blood-feeding pattern of Ur. sapphirina in the northeastern United States, mosquitoes were collected from Massachusetts, Connecticut, and New Jersey using CDC miniature light traps, peat fiber resting boxes, gravid traps, and backpack aspirators. Vertebrate and invertebrate hosts of this mosquito species were identified through PCR amplification and nucleotide sequencing of portions of the mitochondrial cytochrome b gene and the 28S ribosomal RNA gene, respectively. Of 21 (24.7%) specimens successfully identified to host species, 47.6% contained solely annelid blood, 14.3% mammalian blood, 14.3% avian blood, and 23.8% with mixed blood of annelid and avian origin. The mud earthworm, Sparganophilus tennesseensis Reynolds (Haplotaxida: Sparganophilidae), was identified as the most common host (n = 14, including mixed bloods), followed by American robin, Turdus migratorius (n = 7, including mixed bloods). Testing of these blood engorged mosquitoes for West Nile virus and eastern equine encephalitis virus did not result in any positive specimens. This is the first report of Ur. sapphirina feeding on annelids and on both vertebrate and invertebrate hosts in mixed bloodmeals in the northeastern United States. Our findings support the recent report of Ur. sapphirina feeding on invertebrates and further emphasizes the inclination of some mosquito species to feed on a wider range of hosts spanning nontraditional taxonomic groups.

Use of a Miniature Optical Engine for Age Classifying Wild-Caught Coquillettidia perturbans in the Shortwave Infrared Region.

Near-infrared spectroscopy (NIRS), coupled with modeling and chemometrics, has been used to age grade anopheline and aedine mosquitoes; however, NIRS has not been widely used in field studies to assign mosquitoes to age classes. One reason is the relative cost of NIRS spectrometers. We developed a spectrometer system incorporating a miniature optical engine generating spectra in the shortwave infrared region, calibrated it using laboratory-reared Aedes aegypti, and evaluated its utility to age grade wild-caught cattail mosquitoes, Coquillettidia perturbans. As a refinement of the method, we compared a scoring system based on spectral data point outliers with the typical chemometrics that have been used with NIRS. This inexpensive system (<$3,600) could reliably discriminate between age cohorts of mosquitoes and has the potential for more detailed age grading. Laboratory-reared Ae. aegypti demonstrated a decline in the fraction of spectral outliers with age, and field-collected Cq. perturbans similarly demonstrated such a decline (greater in newly emerged mosquitoes) with date of collection, consistent with their univoltine demography in Massachusetts. We conclude that an economical NIRS system may be able to provide a quantitative dichotomous (young versus old) assessment of field-collected mosquito samples, and thereby may be used to complement abundance-based analyses of the efficacy of adulticiding applications.

Estimated Costs and Outcomes Associated With Use and Nonuse of Medications for Opioid Use Disorder During Incarceration and at Release in Massachusetts.

Importance: Most prisons and jails in the US discontinue medications for opioid use disorder (MOUD) upon incarceration and do not initiate MOUD prior to release. Objective: To model the association of MOUD access during incarceration and at release with population-level overdose mortality and OUD-related treatment costs in Massachusetts. Design, Setting, and Participants: This economic evaluation used simulation modeling and cost-effectiveness with costs and quality-adjusted life-years (QALYs) discounted at 3% to compare MOUD treatment strategies in a corrections cohort and an open cohort representing individuals with OUD in Massachusetts. Data were analyzed between July 1, 2021, and September 30, 2022. Exposures: Three strategies were compared: (1) no MOUD provided during incarceration or at release, (2) extended-release (XR) naltrexone offered only at release from incarceration, and (3) all 3 MOUDs (naltrexone, buprenorphine, and methadone) offered at intake. Main Outcomes and Measures: Treatment starts and retention, fatal overdoses, life-years and QALYs, costs, and incremental cost-effectiveness ratios (ICERs). Results: Among 30 000 simulated incarcerated individuals with OUD, offering no MOUD was associated with 40 927 (95% uncertainty interval [UI], 39 001-42 082) MOUD treatment starts over a 5-year period and 1259 (95% UI, 1130-1323) overdose deaths after 5 years. Over 5 years, offering XR-naltrexone at release led to 10 466 (95% UI, 8515-12 201) additional treatment starts, 40 (95% UI, 16-50) fewer overdose deaths, and 0.08 (95% UI, 0.05-0.11) QALYs gained per person, at an incremental cost of $2723 (95% UI, $141-$5244) per person. In comparison, offering all 3 MOUDs at intake led to 11 923 (95% UI, 10 861-12 911) additional treatment starts, compared with offering no MOUD, 83 (95% UI, 72-91) fewer overdose deaths, and 0.12 (95% UI, 0.10-0.17) QALYs per person gained, at an incremental cost of $852 (95% UI, $14-$1703) per person. Thus, XR-naltrexone only was a dominated strategy (both less effective and more costly) and the ICER of all 3 MOUDs compared with no MOUD was $7252 (95% UI, $140-$10 018) per QALY. Among everyone with OUD in Massachusetts, XR-naltrexone only averted 95 overdose deaths over 5 years (95% UI, 85-169)-a 0.9% decrease in state-level overdose mortality-while the all-MOUD strategy averted 192 overdose deaths (95% UI, 156-200)-a 1.8% decrease. Conclusions and Relevance: The findings of this simulation-modeling economic study suggest that offering any MOUD to incarcerated individuals with OUD would prevent overdose deaths and that offering all 3 MOUDs would prevent more deaths and save money compared with an XR-naltrexone-only strategy.

The Chelsea Project: Turning Research and Wastewater Surveillance on COVID-19 Into Health Equity Action, Massachusetts, 2020-2021.

Chelsea, Massachusetts, had one of the highest COVID-19 transmission rates in New England in the summer of 2020. The Chelsea Project was a collaborative effort in which government entities, local nonprofit organizations, and startups partnered to deploy wastewater analysis, targeted polymerase chain reaction testing and vaccine outreach, and a community-led communications strategy. The strategy helped increase both testing rates and vaccination rates in Chelsea. Today Chelsea has one of the highest vaccination rates among US cities with comparable demographics. (Am J Public Health. 2023;113(6):627-630. https://doi.org/10.2105/AJPH.2023.307253).

Opioid-related mortality: Dynamic temporal and spatial trends by drug type and demographic subpopulations, Massachusetts, 2005-2021.

BACKGROUND: Fatal opioid-related overdoses (OOD) present significant public health challenges. Intuitive and replicable analytical approaches are needed to inform targeted public health responses. METHODS: We obtained fatal OOD data for 2005-2021 from the Massachusetts Registry of Vital Records and Statistics. We conducted heatmap analyses to assess trends in fatal OOD rates per 100,000 residents, visualizing rates by death year and decedent age at one-year intervals, stratifying by race/ethnicity, sex, rurality, and involved substances. We calculated Getis-Ord Gi* statistics to identify spatial clusters of OOD rates. RESULTS: Among 20,774 fatal OODs, rates were higher among males, and highly variable by race/ethnicity, age group, and rurality. While fatal OOD rates increased in urban before rural communities, rates were higher in rural communities by 2018-2019. Stimulant-related fatal OODs were elevated in 2020 and 2021. Fatal OOD rates involving fentanyl and stimulants increased precipitously and simultaneously in the non-Hispanic Black population in 2020 and 2021, with a bimodal age distribution peaking among those in their 40s and 60s. Elevated rates among 30-to-60 year old Hispanic residents were largely tied to synthetic opioids from 2015 to 2021. Spatial clusters were detected for prescription opioids, heroin, and stimulants in western Massachusetts. For synthetic opioids, hotspots became more ubiquitous across the state from 2016 to 2021, intensifying in southeastern Massachusetts. CONCLUSION: Our novel approach uncovered new time varying and spatial patterns in fatal OOD rates not previously reported. Identified shifts in fatal OOD rates by sex, age, and race/ethnicity can inform location-specific field actions targeting subpopulations at disproportionally high risk.

Massachusetts General Hospital Hairpulling Scale: Validity and Reliability Study of the Turkish Form. / Massachusetts Genel Hastane Saç/Kil Yolma Ölçegi: Türkçe Formunun Geçerlik ve Güvenirlik Çalismasi.

OBJECTIVE: The aim of this study is to analyze the validity and reliability of the Turkish form of Massachusetts General Hospital Hairpulling Scale (MGH-HPS), which is used to measure the severity of Trichotillomania (TTM). METHODS: Fifty patients diagnosed with TTM according to the DSM-5 diagnostic criteria and fifty healthy controls participated in the study. The participants were asked to complete a sociodemographic questionnaire, the MGH-HPS-TR, the Clinical Global Impression (CGI), the Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI) and the Barratt Impulsiveness Scale (BIS-11). The construct validity and the criterion validity of the MGH-HPS-TR were determined by means of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), respectively. The reliability analysis of the MGH-HPS-TR was assessed by calculating the Cronbach's α coefficient and the item total correlation coefficient. The values for the area under the curve (AUC), sensitivity and specificity were based on the ROC analysis. RESULTS: AFA and CFA results indicated a single factor structure with 7 items explaining 82.5% of the variance. The item/factor loadings were satisfactory with the best fit indeces. Correlations were found between the scores on the MGH-HPS-TR and the other scales used for criterion validity analyses. The internal consistency and the item-total correlation coefficients of the scale were found to be satisfactory. Based on a cut of point of ≥ 9, the scale had high power for discriminating between the patient and the control groups and high sensitivity and specificity. CONCLUSION: This study showed that the MGH-HPS-TR can be used as a valid and reliable psychometric tool in Turkey.

An Interview With Jeanette Ives Erickson, DNP, RN, NEA-BC, FAAN.

At the end of 2022, American Nurses Credentialing Center Magnet Recognition Program® bid farewell to Jeanette Ives Erickson, DNP, RN, NEA-BC, FAAN, as she stepped down as Chair of the Commission on Magnet® (COM). Dr Ives Erickson, the Chief Nurse Emerita and the Distinguished Paul M. Erickson Chair in Nursing at Massachusetts General Hospital (MGH), joined the COM in 2015 as the chief nurse representative. She served a 2nd term as the American Academy of Nursing representative and Commission Chair. As her tenure closed, Dr Ives Erickson shared her thoughts on the nursing profession, changes and challenges in the healthcare environment, and the enduring value of American Nurses Credentialing Center Magnet Recognition Program.

Mortality Trends Among Adults Experiencing Homelessness in Boston, Massachusetts From 2003 to 2018.

This cohort study involves assessing causes of death among people experiencing homelessness in Boston from 2003 to 2018.

Firearm-related lead exposure and pediatric lead levels in Massachusetts: A decade of evidence (2010-2019).

The US has more firearms than any other country in the world and uses lead ammunition almost exclusively. Lead exposure is a significant public health concern and children are at the greatest risk given their exposure to take-home lead. Firearm-related take-home lead exposure may be one of the greatest influences on elevated pediatric blood lead levels. For this ecological and spatial investigation of the relationship between firearm licensure rates as a proxy for firearm-related lead exposure and prevalence of children with blood lead levels ≥5 µg/dL in 351 cities/towns in Massachusetts, we used 10 years of data (2010-2019). We examined this relationship against other known contributors to pediatric lead exposure including old housing stock (lead paint/dust), occupations, and lead in water. Pediatric blood lead levels were positively correlated with licensure, poverty, and certain occupations and negatively correlated with lead in water and police or firefighter employment. Firearm licensure was a major significant predictor of pediatric blood lead alone (ß = 0.13; 95% CI, 0.10, 0.17) and across all regression models. The final model predicted over half the variation in pediatric blood lead (Adjusted R2 = 0.51). Negative binomial analysis found cities/towns with more firearms had higher pediatric blood lead levels (highest quartile fully adjusted prevalence ratio ((aPR) = 1.18; 95% CI, 1.09, 1.30) with a significant increase in pediatric blood lead per increase in firearms (p < 0.001). There were no significant spatial effects, suggesting that although there could be other factors impacting elevated pediatric blood lead, they are unlikely to influence spatial associations. Our paper provides compelling evidence of a potential and dangerous link between lead ammunition and child blood lead levels and is the first to do so using multiple years' worth of data. More research is required to substantiate this relationship on the individual-level and into prevention/mitigation.

Early implementation of full-practice authority: A survey of Massachusetts nurse practitioners.

BACKGROUND: In January 2021, Massachusetts granted nurse practitioners (NPs) full-practice authority (FPA). Little is known about how FPA changes the day-to-day work of NPs. PURPOSE: To examine changes in practice barriers and care delivery in the early stages of FPA. METHODOLOGY: Descriptive analysis of a web-based survey of clinically active NPs in Massachusetts from October to December 2021, using Fisher exact tests to examine the associations between the perception that FPA improved work and other variables. RESULTS: Survey response rate was 50.3% ( N = 147). Overall, 79% of NPs believe that clinical work is unchanged by FPA. Practicing outside institutions is a significant predictor of FPA improving work ( p < .05). Larger proportions of respondents feel that efficiency (22%), patient centeredness (20%), and timeliness (20%) are improved by FPA compared with effectiveness (16%), equity (14%), and safety (10%). Almost half of those reporting that FPA improves overall care also report improved efficiency (50%, p < .0001), but only 22% report improved safety ( p < .05). Of those believing that FPA improved work, a minority no longer need physician review of new controlled substance prescriptions (29%, p < .01), a practice agreement (32%, p < .05), or physician signature on clinical documentation (22%, p < .05). CONCLUSIONS: Almost 1 year after FPA was passed in Massachusetts, the large majority of NPs report no changes in their day-to-day work, suggesting that FPA implementation is slow. IMPLICATIONS: Concerted efforts by regulators, employers, and individual NPs are needed to ensure that legislated FPA is effectively implemented inside organizations and among payers.

Assessing the impact of aircraft arrival on ambient ultrafine particle number concentrations in near-airport communities in Boston, Massachusetts.

Aircraft emissions contribute to overall ambient air pollution, including ultrafine particle (UFP) concentrations. However, accurately ascertaining aviation contributions to UFP is challenging due to high spatiotemporal variability along with intermittent aviation emissions. The objective of this study was to evaluate the impact of arrival aircraft on particle number concentration (PNC), a proxy for UFP, across six study sites 3-17 km from a major arrival aircraft flight path into Boston Logan International Airport by utilizing real-time aircraft activity and meteorological data. Ambient PNC at all monitoring sites was similar at the median but had greater variation at the 95th and 99th percentiles with more than two-fold increases in PNC observed at sites closer to the airport. PNC was elevated during the hours with high aircraft activity with sites closest to the airport exhibiting stronger signals when downwind from the airport. Regression models indicated that the number of arrival aircraft per hour was associated with measured PNC at all six sites, with a maximum contribution of 50% of total PNC at a monitor 3 km from the airport during hours with arrival activity on the flight path of interest (26% across all hours). Our findings suggest strong but intermittent contributions from arrival aircraft to ambient PNC in communities near airports.

Uptake of Per- and Polyfluoroalkyl Substances by Fish, Mussel, and Passive Samplers in Mobile-Laboratory Exposures Using Groundwater from a Contamination Plume at a Historical Fire Training Area, Cape Cod, Massachusetts.

Aqueous film-forming foams historically were used during fire training activities on Joint Base Cape Cod, Massachusetts, and created an extensive per- and polyfluoroalkyl substances (PFAS) groundwater contamination plume. The potential for PFAS bioconcentration from exposure to the contaminated groundwater, which discharges to surface water bodies, was assessed with mobile-laboratory experiments using groundwater from the contamination plume and a nearby reference location. The on-site continuous-flow 21-day exposures used male and female fathead minnows, freshwater mussels, polar organic chemical integrative samplers (POCIS), and polyethylene tube samplers (PETS) to evaluate biotic and abiotic uptake. The composition of the PFAS-contaminated groundwater was complex and 9 PFAS were detected in the reference groundwater and 17 PFAS were detected in the contaminated groundwater. The summed PFAS concentrations ranged from 120 to 140 ng L-1 in reference groundwater and 6100 to 15,000 ng L-1 in contaminated groundwater. Biotic concentration factors (CFb) for individual PFAS were species, sex, source, and compound-specific and ranged from 2.9 to 1000 L kg-1 in whole-body male fish exposed to contaminated groundwater for 21 days. The fish and mussel CFb generally increased with increasing fluorocarbon chain length and were greater for sulfonates than for carboxylates. The exception was perfluorohexane sulfonate, which deviated from the linear trend and had a 10-fold difference in CFb between sites, possibly because of biotransformation of precursors such as perfluorohexane sulfonamide. Uptake for most PFAS in male fish was linear over time, whereas female fish had bilinear uptake indicated by an initial increase in tissue concentrations followed by a decrease. Uptake of PFAS was less for mussels (maximum CFb = 200) than for fish, and mussel uptake of most PFAS also was bilinear. Although abiotic concentration factors were greater than CFb, and values for POCIS were greater than for PETS, passive samplers were useful for assessing PFAS that potentially bioconcentrate in fish but are present at concentrations below method quantitation limits in water. Passive samplers also accumulate short-chain PFAS that are not bioconcentrated.