7 research outputs found
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
Fate of 4-Nonylphenol and 17β-Estradiol in the Redwood River of Minnesota
The majority of previous research investigating the fate of endocrine-disrupting
compounds has focused on single processes generally in controlled
laboratory experiments, and limited studies have directly evaluated
their fate and transport in rivers. This study evaluated the fate
and transport of 4-nonylphenol, 17β-estradiol, and estrone in
a 10-km reach of the Redwood River in southwestern Minnesota. The
same parcel of water was sampled as it moved downstream, integrating
chemical transformation and hydrologic processes. The conservative
tracer bromide was used to track the parcel of water being sampled,
and the change in mass of the target compounds relative to bromide
was determined at two locations downstream from a wastewater treatment
plant effluent outfall. In-stream attenuation coefficients (<i>k</i><sub>stream</sub>) were calculated by assuming first-order
kinetics (negative values correspond to attenuation, whereas positive
values indicate production). Attenuation of 17β-estradiol (<i>k</i><sub>stream</sub> = −3.2 ± 1.0 day<sup>–1</sup>) was attributed primarily due to sorption and biodegradation by
the stream biofilm and bed sediments. Estrone (<i>k</i><sub>stream</sub> = 0.6 ± 0.8 day<sup>–1</sup>) and 4-nonylphenol
(<i>k</i><sub>stream</sub> = 1.4 ± 1.9 day<sup>–1</sup>) were produced in the evaluated 10-km reach, likely due to biochemical
transformation from parent compounds (17β-estradiol, 4-nonylphenolpolyethoxylates,
and 4-nonyphenolpolyethoxycarboxylates). Despite attenuation, these
compounds were transported kilometers downstream, and thus additive
concentrations from multiple sources and transformation of parent
compounds into degradates having estrogenic activity can explain their
environmental persistence and widespread observations of biological
disruption in surface waters
Riverbank filtration potential of pharmaceuticals in a wastewater-impacted stream
Pharmaceutical contamination of shallow groundwater is a substantial concern in effluent-dominated streams, due to high aqueous mobility, designed bioactivity, and effluent-driven hydraulic gradients. In October and December 2012, effluent contributed approximately 99% and 71%, respectively, to downstream flow in Fourmile Creek, Iowa, USA. Strong hydrologic connectivity was observed between surface-water and shallow-groundwater. Carbamazepine, sulfamethoxazole, and immunologically related compounds were detected in groundwater at greater than 0.02 mg L^-1 at distances up to 6 m from the stream bank. Direct aqueous-injection HPLC-MS/MS revealed 43% and 55% of 110 total pharmaceutical analytes in surface-water samples in October and December, respectively, with 16% and 6%, respectively, detected in groundwater approximately 20 m from the stream bank. The results demonstrate the importance of effluent discharge as a driver of local hydrologic conditions in an effluent impacted stream and thus as a fundamental control on surface-water to groundwater transport of effluent-derived pharmaceutical contaminants
Effects of an Extreme Flood on Trace Elements in River WaterFrom Urban Stream to Major River Basin
Major floods adversely affect water
quality through surface runoff,
groundwater discharge, and damage to municipal water infrastructure.
Despite their importance, it can be difficult to assess the effects
of floods on streamwater chemistry because of challenges collecting
samples and the absence of baseline data. This study documents water
quality during the September 2013 extreme flood in the South Platte
River, Colorado, USA. Weekly time-series water samples were collected
from 3 urban source waters (municipal tap water, streamwater, and
wastewater treatment facility effluent) under normal-flow and flood
conditions. In addition, water samples were collected during the flood
at 5 locations along the South Platte River and from 7 tributaries
along the Colorado Front Range. Samples were analyzed for 54 major
and trace elements. Specific chemical tracers, representing different
natural and anthropogenic sources and geochemical behaviors, were
used to compare streamwater composition before and during the flood.
The results differentiate hydrological processes that affected water
quality: (1) in the upper watershed, runoff diluted most dissolved
constituents, (2) in the urban corridor and lower watershed, runoff
mobilized soluble constituents accumulated on the landscape and contributed
to stream loading, and (3) flood-induced groundwater discharge mobilized
soluble constituents stored in the vadose zone
Persistence and Potential Effects of Complex Organic Contaminant Mixtures in Wastewater-Impacted Streams
Natural and synthetic organic contaminants in municipal
wastewater
treatment plant (WWTP) effluents can cause ecosystem impacts, raising
concerns about their persistence in receiving streams. In this study,
Lagrangian sampling, in which the same approximate parcel of water
is tracked as it moves downstream, was conducted at Boulder Creek,
Colorado and Fourmile Creek, Iowa to determine in-stream transport
and attenuation of organic contaminants discharged from two secondary
WWTPs. Similar stream reaches were evaluated, and samples were collected
at multiple sites during summer and spring hydrologic conditions.
Travel times to the most downstream (7.4 km) site in Boulder Creek
were 6.2 h during the summer and 9.3 h during the spring, and to the
Fourmile Creek 8.4 km downstream site times were 18 and 8.8 h, respectively.
Discharge was measured at each site, and integrated composite samples
were collected and analyzed for >200 organic contaminants including
metal complexing agents, nonionic surfactant degradates, personal
care products, pharmaceuticals, steroidal hormones, and pesticides.
The highest concentration (>100 μg L<sup>–1</sup>)
compounds
detected in both WWTP effluents were ethylenediaminetetraacetic acid
and 4-nonylphenolethoxycarboxylate oligomers, both of which persisted
for at least 7 km downstream from the WWTPs. Concentrations of pharmaceuticals
were lower (<1 μg L<sup>–1</sup>), and several compounds,
including carbamazepine and sulfamethoxazole, were detected throughout
the study reaches. After accounting for in-stream dilution, a complex
mixture of contaminants showed little attenuation and was persistent
in the receiving streams at concentrations with potential ecosystem
implications