Dietary Uptake of Highly Hydrophobic Chemicals by Rainbow Trout (Oncorhynchus Mykiss).

Rainbow trout (Oncorhynchus mykiss) was exposed through the diet to a mixture of non-ionic organic chemicals for 28 d, followed by a depuration phase, in accordance with OECD method 305. The mixture included hexachlorobenzene (HCB), 2,2',5,5'-tetrachlorobiphenyl (PCB-52), 2,2',5,5'-hexachlorobiphenyl (PCB-153), decachlorobiphenyl (PCB-209), decabromodiphenyl ether (BDE209), decabromodiphenyl ethane (DBDPE), bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH), perchloro-p-terphenyl (p-TCP), perchloro-m-terphenyl (m-TCP), and perchloro-p-quaterphenyl (p-QTCP), the latter six of which are considered highly hydrophobic based on n-octanol/water partition coefficients (KOW) greater than 108. All chemicals had first-order uptake and elimination kinetics except p-QTCP, whose kinetics could not be verified due to limitations of analytical detection in the elimination phase. For HCB and PCBs, the growth-corrected elimination rates (k2g), assimilation efficiencies (α), and biomagnification factors (BMFL) corrected for lipid content compared well with literature values. For the highly hydrophobic chemicals, elimination rates were faster than the rates for HCB and PCBs, and α's and BMFLs were much lower than those of HCB and PCBs, i.e., ranging from 0.019 to 2.8%, and from 0.000051 to 0.023 (g-lipid/g-lipid), respectively. As a result, the highly hydrophobic organic chemicals were found be much less bioavailable and bioaccumulative than HCB and PCBs. Based on the current laboratory dietary exposures, none of the highly hydrophobic substances would be expected to biomagnify, but Trophic Magnification Factors (TMFs) > 1 have been reported from field studies for TBPH and DBDPE. Additional research is needed to understand and reconcile the apparent inconsistencies in these two lines of evidence for bioaccumulation assessment.

Biosurveillance of Drug Overdoses and Substance Misuse Treated in Selected Emergency Departments in Minnesota, 2017-2020.

OBJECTIVES: Increasing knowledge about the toxicology of drug overdose and substance misuse (DOSM) is important in improving our understanding of the epidemic. We describe the Minnesota Drug Overdose and Substance Use Pilot Surveillance Activity, which started collecting data on emergency department (ED) visits attributable to DOSM in 2017, with a focus on the toxicology results of a subset of clinical encounters. METHODS: From November 1, 2017, through January 30, 2020, we collected near-real-time data on DOSM-related ED encounters. The Minnesota Department of Health Public Health Laboratory tested leftover clinical specimens (blood and/or urine) for the presence of various substances for patients who died, were hospitalized, had an atypical clinical presentation, or were part of a local drug overdose cluster. Testing looked for >250 drugs or their metabolites, including those commonly misused (eg, methamphetamine, cocaine), prescription medications, synthetic cannabinoids and cathinones, and opioids. We describe characteristics of the overall group and a subgroup of clinical encounters with toxicology results. RESULTS: Specimens submitted from 6 EDs during the study period represented 239 clinical encounters. Methamphetamine was the most frequently detected substance (67.4%) but was suspected in only 45.6% of encounters. At least 1 opioid was detected in 42.5% of encounters but suspected in only 29.7%. Testing also detected potential adulterants and additives (eg, fentanyl, fentanyl analogues, levamisole) and showed frequent patient exposure to substances not reported by patients or suspected by clinicians. Nearly half (44.4%) of clinical encounters had >1 substance detected. CONCLUSIONS: ED surveillance for DOSM encounters, enhanced by toxicology testing, can provide local situational awareness on overdoses, prevent potential mischaracterization of the true drug overdose epidemic, and inform harm reduction and drug overdose prevention efforts.

Characteristics of E-cigarette, or Vaping, Products Used by Patients with Associated Lung Injury and Products Seized by Law Enforcement - Minnesota, 2018 and 2019.

During August 9-October 31, 2019, 96 patients were classified as having e-cigarette, or vaping, product use-associated lung injury (EVALI) by the Minnesota Department of Health (MDH); other patients are being investigated for case classification and exposures. Among 58 patients interviewed, 53 (91%) reported obtaining tetrahydrocannabinol (THC)-containing products from informal sources such as friends, family members, or in-person or online dealers. Using gas chromatography-mass spectrometry (GCMS), the MDH Public Health Laboratory (PHL) analyzed 46 THC-containing e-cigarette, or vaping, products obtained from 12 EVALI patients for various potential toxicants, including vitamin E acetate, which has recently been detected in some THC-containing products and in samples of lung fluid from EVALI patients (1-4). To explore whether vitamin E acetate is a recently added component in THC-containing products, MDH tested ten products seized by law enforcement in 2018, before the EVALI outbreak, and 20 products seized in 2019, during the outbreak. Twenty-four products obtained from 11 EVALI patients from 2019 contained vitamin E acetate. Among the seized products tested by MDH, none seized in 2018 contained vitamin E acetate, although all tested THC-containing products seized in 2019 tested positive for vitamin E acetate. These chemical analyses of products obtained from EVALI patients and of products intended for the illicit market both before and during the outbreak support a potential role for vitamin E acetate in the EVALI outbreak; however, the number of products tested was small, and further research is needed to establish a causal link between exposure to inhaled vitamin E acetate and EVALI. Collaboration between public health jurisdictions and law enforcement to characterize THC-containing products circulating before the recognition of the EVALI outbreak and during the outbreak might provide valuable information about a dynamic market. These Minnesota findings highlight concerns about e-cigarette, or vaping, products that contain THC acquired from informal sources. Because local supply chains and policy environments vary, CDC continues to recommend not using e-cigarette, or vaping, products that contain THC or any e-cigarette, or vaping, products obtained from informal sources. E-cigarette, or vaping, products should never be used by youths, young adults, or pregnant women.* Until the relationship between inhaled vitamin E acetate and lung health is better characterized, vitamin E acetate should not be added to e-cigarette, or vaping, products.

Estimating n-octanol-water partition coefficients for neutral highly hydrophobic chemicals using measured n-butanol-water partition coefficients.

Direct measurement of the n-octanol partition coefficients (KOW) for highly hydrophobic organic chemicals is extremely difficult because of the extremely low concentrations present in the water phase. n-Butanol/water partition coefficients (KBW) are generally much lower than KOW due to the increased solubility of solute in the alcohol saturated aqueous phase, and therefore become easier to measure. We measured the KBW for 25 neutral organic chemicals having measured log KOWs ranging from 2 to 9 and 4 additional highly hydrophobic chemicals, with unmeasured KOWs, having estimated log KOWs ranging from 6 to 18. The measured log KBW and log KOW values were linearly related, r2 = 0.978, and using the regression developed from the data, KOWs were predicted for the 4 highly hydrophobic chemicals with unmeasured KOWs. The resulting predictions were orders of magnitude lower than those predicted by a variety of computational models and suggests the estimates of KOW in the literature for highly hydrophobic chemicals (i.e., log KOW greater than 10) are likely incorrect by several orders of magnitude.