5 research outputs found
Appendix B. Lake Hartwell water elevation 1962–2007.
Lake Hartwell water elevation 1962–2007
Appendix A. Location of study area and sampling sites.
Location of study area and sampling sites
Uptake of Perfluoroalkyl Acids into Edible Crops via Land Applied Biosolids: Field and Greenhouse Studies
The presence of perfluoroalkyl acids
(PFAAs) in biosolids destined
for use in agriculture has raised concerns about their potential to
enter the terrestrial food chain via bioaccumulation in edible plants.
Uptake of PFAAs by greenhouse lettuce (Lactuca sativa) and tomato (Lycopersicon lycopersicum) grown in an industrially impacted biosolids-amended soil, a municipal
biosolids-amended soil, and a control soil was measured. Bioaccumulation
factors (BAFs) were calculated for the edible portions of both lettuce
and tomato. Dry weight concentrations observed in lettuce grown in
a soil amended (biosolids:soil dry weight ratio of 1:10) with PFAA
industrially contaminated biosolids were up to 266 and 236 ng/g for
perfluorobutanoic acid (PFBA) and perfluoropentanoic acid (PFPeA),
respectively, and reached 56 and 211 ng/g for PFBA and PFPeA in tomato,
respectively. BAFs for many PFAAs were well above unity, with PFBA
having the highest BAF in lettuce (56.8) and PFPeA the highest in
tomato (17.1). In addition, the BAFs for PFAAs in greenhouse lettuce
decreased approximately 0.3 log units per CF<sub>2</sub> group. A
limited-scale field study was conducted to verify greenhouse findings.
The greatest accumulation was seen for PFBA and PFPeA in both field-grown
lettuce and tomato; BAFs for PFBA were highest in both crops. PFAA
levels measured in lettuce and tomato grown in field soil amended
with only a single application of biosolids (at an agronomic rate
for nitrogen) were predominantly below the limit of quantitation (LOQ).
In addition, corn (Zea mays) stover,
corn grains, and soil were collected from several full-scale biosolids-amended
farm fields. At these fields, all PFAAs were below the LOQ in the
corn grains and only trace amounts of PFBA and PFPeA were detected
in the corn stover. This study confirms that the bioaccumulation of
PFAAs from biosolids-amended soils depends strongly on PFAA concentrations,
soil properties, the type of crop, and analyte
Perfluoroalkyl Acid Distribution in Various Plant Compartments of Edible Crops Grown in Biosolids-Amended soils
Crop
uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended
soil has been identified as a potential pathway for PFAA entry into
the terrestrial food chain. This study compared the uptake of PFAAs
in greenhouse-grown radish (<i>Raphanus sativus</i>), celery
(<i>Apium graveolens</i> var. <i>dulce</i>), tomato
(<i>Lycopersicon lycopersicum</i>), and sugar snap pea (<i>Pisum sativum </i>var.<i> macrocarpon</i>) from an
industrially impacted biosolids-amended soil, a municipal biosolids-amended
soil, and a control soil. Individual concentrations of PFAAs, on a
dry weight basis, in mature, edible portions of crops grown in soil
amended with PFAA industrially impacted biosolids were highest for
perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate
(PFBA; 232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit.
Comparatively, PFAA concentrations in edible compartments of crops
grown in the municipal biosolids-amended soil and in the control soil
were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated
for the root, shoot, and fruit compartments (as applicable) of all
crops grown in the industrially impacted soil. BAFs were highest for
PFBA in the shoots of all crops, as well as in the fruit compartment
of pea. Root-soil concentration factors (RCFs) for tomato and pea
were independent of PFAA chain length, while radish and celery RCFs
showed a slight decrease with increasing chain length. Shoot-soil
concentration factors (SCFs) for all crops showed a decrease with
increasing chain length (0.11 to 0.36 log decrease per CF<sub>2</sub> group). The biggest decrease (0.54–0.58 log decrease per
CF<sub>2</sub> group) was seen in fruit-soil concentration factors
(FCFs). Crop anatomy and PFAA properties were utilized to explain
data trends. In general, fruit crops were found to accumulate fewer
long-chain PFAAs than shoot or root crops presumably due to an increasing
number of biological barriers as the contaminant is transported throughout
the plant (roots to shoots to fruits). These data were incorporated
into a preliminary conceptual framework for PFAA accumulation in edible
crops. In addition, these data suggest that edible crops grown in
soils conventionally amended for nutrients with biosolids (that are
not impacted by PFAA industries) are unlikely a significant source
of long-chain PFAA exposure to humans
Expanded Target-Chemical Analysis Reveals Extensive Mixed-Organic-Contaminant Exposure in U.S. Streams
Surface water from
38 streams nationwide was assessed using 14
target-organic methods (719 compounds). Designed-bioactive anthropogenic
contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics
detected at least once. The 10 most-frequently detected anthropogenic-organics
included eight pesticides (desulfinylfipronil, AMPA, chlorpyrifos,
dieldrin, metolachlor, atrazine, CIAT, glyphosate) and two pharmaceuticals
(caffeine, metformin) with detection frequencies ranging 66–84%
of all sites. Detected contaminant concentrations varied from less
than 1 ng L<sup>–1</sup> to greater than 10 μg L<sup>–1</sup>, with 77 and 278 having median detected concentrations
greater than 100 ng L<sup>–1</sup> and 10 ng L<sup>–1</sup>, respectively. Cumulative detections and concentrations ranged 4–161
compounds (median 70) and 8.5–102 847 ng L<sup>–1</sup>, respectively, and correlated significantly with wastewater discharge,
watershed development, and toxic release inventory metrics. Log<sub>10</sub> concentrations of widely monitored HHCB, triclosan, and
carbamazepine explained 71–82% of the variability in the total
number of compounds detected (linear regression; <i>p</i>-values: < 0.001–0.012), providing a statistical inference
tool for unmonitored contaminants. Due to multiple modes of action,
high bioactivity, biorecalcitrance, and direct environment application
(pesticides), designed-bioactive organics (median 41 per site at μg
L<sup>–1</sup> cumulative concentrations) in developed watersheds
present aquatic health concerns, given their acknowledged potential
for sublethal effects to sensitive species and lifecycle stages at
low ng L<sup>–1</sup>