Role of Plant Bioassays in FDA Review: Scenarios for Terrestrial Exposures

Harrass, MC; Eirkson, CE; Nowell, LH

doi:10.1520/stp19500s

Cited by 5 publications

(5 citation statements)

References 10 publications

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“…A substance is considered toxic by the USFDA if the maximum environmental concentration exceeds the concentration of that chemical that is found to cause adverse effects in test species, or exceeds 1% of the LC 50 (Harrass et al 1991). The USFDA, established in 1906 during the Woodrow Wilson administration, has regulatory authority over the testing and approval of chemicals used in the manufacture and production of food additives, food processing, and the chemicals used in processing products from animals.…”

Section: Plants and Toxicity Assessmentmentioning

confidence: 99%

Introduction to Phytoremediation of Contaminated Groundwater

Landmeyer

2012

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Library of Congress Control Number: 2011937578# Springer ScienceþBusiness Media B.V. 2012 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Cover image: # 2011 JupiterImages CorporationPrinted on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) The deeper the roots, the higher the reach To Lori, Kaylee, and Ava-May our roots always find deep water.. Preface "Nature is driven by water"Leonardo da Vinci (from Richter 1888)Groundwater is one of our most important natural resources. Groundwater provides drinking water to more than 50% of the population of the United States. This fact may not surprise a domestic-well owner, but may surprise municipal water customers who drink tap water supplied by wells. A greater percentage of the population in other countries, particularly in the developing world, relies on groundwater. Groundwater usually requires minimal treatment prior to drinking as groundwater is filtered during flow through porous sediments. Moreover, groundwater can be decades to thousands of years old and, therefore, contain precipitation that fell long before the production and release of modern-day contaminants.These facts do not imply groundwater is protected from contamination. On the contrary, groundwater resources can be more vulnerable to contamination than surface water. For example, contaminant sources may be located a short vertical distance above shallow groundwater that typically is discharged to surface water or pumped by wells after only a few years in the subsurface with correspondingly little time for contaminant cleansing to occur. Alternatively, the slow groundwater-flow rates characteristic of deep groundwater means that contamination will take more time to be discharged from aquifers. In both cases, contamination of groundwater should be avoided if at all possible. If contamination occurs, remediation of groundwater to pre-contamination conditions should be accomplished as efficiently, as quickly, and as cost effectively as possible to ensure that current and future demands on the groundwater resource can be met.Phytoremediation is one of many potential alternatives that can be used to restore contaminated groundwater. In general, phytoremediation is the use of living organisms-plantsto restore contaminated environments to less harmful levels. It is commonly accepted that plants have the potential to cleanse the air, such as taking in carbon dioxide (CO 2 ) and releasing oxygen (O 2 ). But plants also have the potential to cleanse water. This is because water controls all aspects of plant survival; a glance at the waterless and plantless moon quickly confirms this statement. From seed to maturit...

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Section: Plants and Toxicity Assessmentmentioning

confidence: 99%

Introduction to Phytoremediation of Contaminated Groundwater

Landmeyer

2012

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“…Digested sludge (C ds )-dry weight basis C ds ϭ C iw ϫ ratio of wastewater flow to sludge flow ϫ fraction of material removed but not degraded [18] Sludge-amended soil (C soil )single application C soil ϭ C ds ϫ sludge application rate Ϭ soil incorporation depth ϫ soil bulk density [24] Sludge-amended soil (C soil )-at steady state [14]. 96% of POTW sewage flow receives secondary treatment (ϳ75% as activated sludge); 4% receives primary treatment only [19].…”

Section: Predicted Environmental Concentrationsmentioning

confidence: 99%

“…Default assumptions used in the derivation of sludge amended soil PECs for the PE and RP materials include the following-the ratio of wastewater flow to sludge flow is 260 [18]. A typical sludge application rate is 2.2 mg/m 2 (applied once per year), the soil incorporation depth for sludge is 15 cm, and the soil bulk density for agricultural soil is 1,200 kg/ m 3 [24].…”

Section: Predicted Environmental Concentrationsmentioning

confidence: 99%

An environmental risk assessment profile of two synthetic polymers

Guiney

Woltering

Jop

1998

Enviro Toxic and Chemistry

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A number of environmental fate and effects studies on two distinctly different polycarboxylates were conducted as part of a product stewardship program. These studies led to the development of an environmental risk assessment for the two materials. Polymer emulsion (PE) is a typical anionic, styrene‐acrylic polymer (MW 50,000–60,000) used in coating applications. Resin polymer (RP), insoluble at neutral pH but increasingly soluble at pH ≥8, is a neutral‐charged, styrene‐acrylic polymer (molecular weight 4,500–9,000) used primarily for graphic arts products. Some amount of both materials will enter the environment given their use and disposal patterns. Their environmental fate is driven by physical‐chemical characteristics. Both polymers demonstrated low biodegradation and bioaccumulation potential and strong sorption to soils, sludge, and sediments in laboratory and/or field studies. Ecotoxicity test results on a variety of plant and animal species indicated a very low order of acute and chronic toxicity. The environmental risk assessment included characterization of exposure in relevant environmental matrices, characterization of adverse effects or hazards to receptors for which there are complete exposure pathways, and characterization of risk by comparison of predicted exposure levels to adverse effect threshold levels. Based on conservative exposure assumptions, the safety margins established in this assessment indicate that the use of PE and RP, in both commercial and household applications, presents a very low risk to aquatic organisms in the water column and sediments, as well as to terrestrial plants, invertebrates, and wildlife. These polymers are also compatible with wastewater and solid waste treatment systems.

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“…Projected levels of olestra in POTW sludge and subsequently in a sludge-amended agricultural soil were calculated using methods from Holman [16] and Harrass et al [32]. For the purposes of the assessment, the calculations made the conservative assumptions that 100% of olestra entering a treatment plant is removed and goes to soil as a component of sludge.…”

Section: Municipal Sludge and Agricultural Soil Concentrationsmentioning

confidence: 99%

Environmental assessment of a new food ingredient, the fat replacer olestra

Allgood

McAvoy

Woltering

1997

Enviro Toxic and Chemistry

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Olestra is a new noncaloric food ingredient made from sugar and vegetable oil combined in such a way that it is not digested or absorbed. Olestra will be used to replace the cooking fat and oils used to make savory snacks such as potato chips. An environmental assessment (EA) was conducted to determine whether or not this consumer use of olestra would result in adverse impacts to the environment. The EA was also submitted to the U.S. Food and Drug Administration as part of the agency's review and approval process for this new food ingredient. To provide a conservative assessment, that is, to not underestimate potential environmental risk, exposure estimates were based on an upper‐bound annual consumption value of 228 × 106 kg (about 500 million pounds) and the assumption that the entire amount would enter wastewater. The olestra environmental database is extensive and includes studies to address its fate and effects in wastewater treatment systems, sludge‐amended soils, and receiving waters. Testing showed olestra was not toxic to aquatic organisms including bacteria, algae, zooplankton, and fish nor to terrestrial organisms including bacteria, plants, earthworms, and nine mammalian species. Testing also showed olestra will not bioconcentrate or persist. Aerobic biodegradation was demonstrated in both aquatic and terrestrial matrices and a plausible mineralization pathway was detailed that has application to both aerobic and anaerobic environments. Because of its very low water solubility (5–42 μg/L) and sorptive nature (Kd ranging from 10,000 to 287,000 L/kg), the vast majority of olestra that enters the environment will be associated with wastewater solids and sludges. Overall removal for primary and secondary treatment was 91 to 94%. Olestra was shown to be mineralized at a rate sufficient to prevent significant accumulation in soil even with annual reapplication of sludge (half‐lives were 10–88 d depending upon the physical form [liquid or solid] of olestra). Laboratory and bench scale testing showed olestra did not adversely effect conventional wastewater treatment. Olestra exhibited no adverse effects on total suspended solids or chemical oxygen demand. Olestra's properties are compatible with disposal in landfills and by incineration. Olestra did not adversely impact full‐scale septic tanks or physical properties of sludge‐amended agricultural soils. Based on conservative exposure estimates and extensive testing, the evidence indicates that consumer use of olestra will not result in adverse effects on wastewater treatment or aquatic and terrestrial ecosystems.

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Role of Plant Bioassays in FDA Review: Scenarios for Terrestrial Exposures

Cited by 5 publications

References 10 publications

Introduction to Phytoremediation of Contaminated Groundwater

Introduction to Phytoremediation of Contaminated Groundwater

An environmental risk assessment profile of two synthetic polymers

Environmental assessment of a new food ingredient, the fat replacer olestra

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