Environmental toxicology

Does Long-Term Irrigation with Untreated Wastewater Accelerate the Dissipation of Pharmaceuticals in Soil?

Philipp Dalkmann, Christina Siebe, Wulf Amelung, Michael Schloter, and Jan Siemens (2014). “Does Long-Term Irrigation with Untreated Wastewater Accelerate the Dissipation of Pharmaceuticals in Soil?” Environmental Science & Technology 48 (9), 4963-4970. DOI: 10.1021/es501180x

Abstract: Long-term irrigation with untreated wastewater may increase soil microbial adaptation to pollution load and lead to enhanced natural attenuation. We hypothesized that long-term wastewater irrigation accelerates the dissipation of pharmaceuticals. To test our hypothesis we performed an incubation experiment with soils from the Mezquital Valley, Mexico that were irrigated for 0, 14, or 100 years. The results showed that the dissipation half-lives (DT50) of diclofenac (<0.1–1.4 days), bezafibrate (<0.1–4.8 days), sulfamethoxazole (2–33 days), naproxen (6–19 days), carbamazepine (355–1,624 days), and ciprofloxacin were not affected by wastewater irrigation. Trimethoprim dissipation was even slower in soils irrigated for 100 years (DT50: 45–72 days) than in nonirrigated soils (DT50: 12–16 days), was negatively correlated with soil organic matter content and soil-water distribution coefficients, and was inhibited in sterilized soils. Applying a kinetic fate model indicated that long-term irrigation enhanced sequestration of cationic or uncharged trimethoprim and uncharged carbamazepine, but did not affect sequestration of fast-dissipating zwitterions or negatively charged pharmaceuticals. We conclude that microbial adaptation processes play a minor role for pharmaceutical dissipation in wastewater-irrigated soils, while organic matter accumulation in these soils can retard trimethoprim and carbamazepine dissipation.

Strong Sorption of PCBs to Nanoplastics, Microplastics, Carbon Nanotubes, and Fullerenes

I. Velzeboer, C. J. A. F. Kwadijk, and A. A. Koelmans (2014). “Strong Sorption of PCBs to Nanoplastics, Microplastics, Carbon Nanotubes, and Fullerenes.” Environmental Science & Technology 48 (9), 4869-4876. DOI: 10.1021/es405721v.

Abstract: The presence of microplastic and carbon-based nanoparticles in the environment may have implications for the fate and effects of traditional hydrophobic chemicals. Here we present parameters for the sorption of 17 CB congeners to 10–180 μm sized polyethylene (micro-PE), 70 nm polystyrene (nano-PS), multiwalled carbon nanotubes (MWCNT), fullerene (C60), and a natural sediment in the environmentally relevant 10–5–10–1 μg L–1 concentration range. Effects of salinity and sediment organic matter fouling were assessed by measuring the isotherms in fresh- and seawater, with and without sediment present. Sorption to the “bulk” sorbents sediment organic matter (OM) and micro-PE occurred through linear hydrophobic partitioning with OM and micro-PE having similar sorption affinity. Sorption to MWCNT and nano-PS was nonlinear. PCB sorption to MWCNT and C60 was 3–4 orders of magnitude stronger than to OM and micro-PE. Sorption to nano-PS was 1–2 orders of magnitude stronger than to micro-PE, which was attributed to the higher aromaticity and surface–volume ratio of nano-PS. Organic matter effects varied among sorbents, with the largest OM fouling effect observed for the high surface sorbents MWCNT and nano-PS. Salinity decreased sorption for sediment and MWCNT but increased sorption for the polymers nano-PS and micro-PE. The exceptionally strong sorption of (planar) PCBs to C60, MWCNT, and nano-PS may imply increased hazards upon membrane transfer of these particles.

Record levels of banned insecticide found in Illinois otters

Read the full story in Great Lakes Echo, which features research from the Illinois Natural History Survey.

The river otter – sleek swimmer, audience-magnets at zoos and aquariums, whiskered diver, aquatic frolicker, correct answer to crossword puzzle clue for “playful mammal.”

And biomonitor to track toxics that damage the health of an environment or ecosystem.

North American river otters play that role because they’re “apex consumers” in the aquatic ecosystem – meaning they’re at the top of the food chain. They eat primarily aquatic animals such as fish, turtles, amphibians and crayfish.

Exposure Science in the 21st Century: A Vision and a Strategy

Download the free PDF. Hard copy is $47.00 from National Academies Press.

From the use of personal products to our consumption of food, water, and air, people are exposed to a wide array of agents each day–many with the potential to affect health. Exposure Science in the 21st Century: A Vision and A Strategy investigates the contact of humans or other organisms with those agents (that is, chemical, physical, and biologic stressors) and their fate in living systems. The concept of exposure science has been instrumental in helping us understand how stressors affect human and ecosystem health, and in efforts to prevent or reduce contact with harmful stressors. In this way exposure science has played an integral role in many areas of environmental health, and can help meet growing needs in environmental regulation, urban and ecosystem planning, and disaster management.

Exposure Science in the 21st Century: A Vision and A Strategy explains that there are increasing demands for exposure science information, for example to meet needs for data on the thousands of chemicals introduced into the market each year, and to better understand the health effects of prolonged low-level exposure to stressors. Recent advances in tools and technologies–including sensor systems, analytic methods, molecular technologies, computational tools, and bioinformatics–have provided the potential for more accurate and comprehensive exposure science data than ever before. This report also provides a roadmap to take advantage of the technologic innovations and strategic collaborations to move exposure science into the future.

Release 3.1 of AQUATOX now available

AQUATOX is a simulation model for aquatic systems. AQUATOX predicts the fate of various pollutants, such as nutrients and organic chemicals, and their effects on the ecosystem, including fish, invertebrates, and aquatic plants. This model is a valuable tool for ecologists, biologists, water quality modelers, and anyone involved in performing ecological risk assessments for aquatic ecosystems. Although incorporating constructs from classic ecosystem and chemodynamic models, AQUATOX was developed from the beginning as an applied model for use by environmental analysts.

Release 3.1 of AQUATOX is now available. Release 3.1 contains several enhancements over previous releases that improve the model’s interface and utility.  For example, the sediment diagenesis model has a “steady-state” mode that increases model speed dramatically.  Other categories of refinements include floating-plants refinements, bioaccumulation and toxicity modeling improvements, and improved sensitivity and uncertainty analyses.

Ecotoxicology of lead shot and benefits of alternatives — a compilation

There has been a lot of recent press coverage about the ecotoxicology of lead shot and the benefits of alternatives. Some recent articles are:

Myra E. Finkelstein, Daniel F. Doak, Daniel George, Joe Burnett, Joseph Brandt, Molly Church, Jesse Grantham, and Donald R. Smith. (2012). “Lead poisoning and the deceptive recovery of the critically endangered California condor”. Proceedings of the National Academy of Sciences Published online before print June 25, 2012, doi: 10.1073/pnas.1203141109
Abstract: Endangered species recovery programs seek to restore populations to self-sustaining levels. Nonetheless, many recovering species require continuing management to compensate for persistent threats in their environment. Judging true recovery in the face of this management is often difficult, impeding thorough analysis of the success of conservation programs. We illustrate these challenges with a multidisciplinary study of one of the world’s rarest birds—the California condor (Gymnogyps californianus). California condors were brought to the brink of extinction, in part, because of lead poisoning, and lead poisoning remains a significant threat today. We evaluated individual lead-related health effects, the efficacy of current efforts to prevent lead-caused deaths, and the consequences of any reduction in currently intensive management actions. Our results show that condors in California remain chronically exposed to harmful levels of lead; 30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects, measured as >60% inhibition of the heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ∼20% of free-flying birds have blood lead levels (≥450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality. Lead isotopic analysis shows that lead-based ammunition is the principle source of lead poisoning in condors. Finally, population models based on condor demographic data show that the condor’s apparent recovery is solely because of intensive ongoing management, with the only hope of achieving true recovery dependent on the elimination or substantial reduction of lead poisoning rates.

News stories covering this study

Joel E. Pagel, Peter B. Sharpe, David K. Garcelon, Annie E. Little, Sharon K. Taylor, Kate R. Faulkner, and Carol S. Gorbics. (2012) “Exposure of Bald Eagles to Lead on the Northern Channel Islands, California.” Journal of Raptor Research 46(2):168-176. doi: http://dx.doi.org/10.3356/JRR-11-18.1
Abstract: Bald Eagles (Haliaeetus leucocephalus) were one of the upper-trophic-level avian predators on the Channel Islands, California, prior to their extirpation by 1960 caused in part by large amounts of DDT discharged into the Southern California Bight. From 2002 to 2006, 61 Bald Eagles were reintroduced onto the northern Channel Islands, as part of a 5-yr feasibility study conducted under the auspices of the Montrose Settlement Restoration Program. In December 2005, a yearling Bald Eagle female was found on Santa Rosa Island with a broken wing and elevated lead levels in her blood of 52.2 ug/dl (0.522 ppm). This incident raised concerns that lead poisoning could be a potential threat to the restoration effort and prompted further investigation. Femurs from five female and two male Bald Eagles reintroduced to the northern Channel Islands were collected postmortem for analyses of lead and other metals. Lead levels detected in femurs of these birds ranged from 0.2 to 55.0 ppm (dry weight). Lead levels in liver were also determined for two of the seven Bald Eagles. Analysis of Bald Eagle movement data from satellite telemetry transmitters suggested that eagles that spent the most time on Santa Rosa Island had the highest lead levels. The results of this study suggested that spent ammunition containing lead found in carrion (offal and entire carcasses) from deer and elk hunting on Santa Rosa Island may have been a primary source of contamination. The on-island hunt program converted to nontoxic bullets in 2007 and ended in late 2011.

Copper Opportunities: Copper Ammo Emerging as the “Bullet of Choice” among Minnesota Deer Hunters (Whitetales)
One favorite tradition among deer hunters is sharing the stories of the hunt following each year’s deer season. This year there are some new and compelling stories emerging from hunters who have switched to copper bullets for deer hunting.

Oil Dispersants: Additional Research Needed, Particularly on Subsurface and Arctic Applications

Oil Dispersants: Additional Research Needed, Particularly on Subsurface and Arctic Applications. GAO-12-585, May 30.
http://www.gao.gov/products/GAO-12-585
Highlights: http://www.gao.gov/assets/600/591233.pdf