Linda Schweitzer - Academia.edu (original) (raw)

Papers by Linda Schweitzer

Water Science and Technology, 2004

A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, ... more A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, 2001 for the purpose of developing a method for testing drinking water system components for their potential to contribute to taste-and-odor problems in drinking water. The workshop participants derived a method using provisions from European Standards as well as newly developed approaches. It is intended that this method can serve as a temporary procedure for water utilities, as well as a recommended template to derive an official standard. Materials to be tested may include pipes, fittings, ancillaries, joints, lubricants, tanks, and reservoirs. The recommended method includes a migration (leaching) test with chlorinated water, followed by sensory analysis of the samples from the migration test after dechlorination. Sensory analyses use both statistical (e.g., triangle test) and descriptive (e.g. Flavor Profile Analysis) techniques. A decision tree for the results is provided.

Environmental Toxicology and Chemistry, 2000

The dietary assimilation of a polychlorinated biphenyl (PCB) in adult sea urchins and the effects... more The dietary assimilation of a polychlorinated biphenyl (PCB) in adult sea urchins and the effects of maternal transfer of the PCB on sea urchin offspring were investigated and compared to an earlier study where this PCB produced toxicity to developing sea urchin embryos exposed directly through the water route. Adult sea urchins were allowed to graze on sediment spiked with radiolabeled PCB, 2,2′,4,4′‐tetrachlorobiphenyl, for 35 days. The sea urchin L. pictus was found to have a high pollutant extraction efficiency; approx. 62% of the bulk PCB sediment concentration is removed while passing through the gut. Maternal transfer of PCB 2,2′,4,4′‐tetrachlorobiphenyl did not prove to be a more sensitive exposure route to developing embryos than the direct water route. Both adult sea urchins and their offspring were found to be resilient to the effects of this PCB at environmentally relevant sediment concentrations and at levels expected on the basis of the critical body residue theory or ...

The effects of maternal transfer of polychlorinated biphenyl (PCB) Congener 47 on sea urchin offs... more The effects of maternal transfer of polychlorinated biphenyl (PCB) Congener 47 on sea urchin offspring were investigated and compared to the toxicity produced by exposure of sea urchin embryos to this PCB dissolved in seawater. Adult sea urchins were exposed to sediments spiked with the PCB Congener 47 (2,2’,4,4’tetrachlorobiphenyl) at concentrations of 0, 0.5, 5, and 20 mg/kg dry wt. The sea urchins were spawned after a 35-d exposure to the PCB, and the embryos were measured for bioaccumulation and toxic effects. Toxicity was also evaluated in adult sea urchins by measuring growth rate and gonadal somatic index (GSI, percent of weight which is gonad) at the different doses. Maternal transfer of Congener 47 was substantial, approximately 30% of the mass of PCB in adults was contained within eggs. No toxic effects were detected in the PCB-exposed embryos or adults. The results of this experiment indicate that sea urchin embryos exposed to PCB from maternal transfer are no more sensit...

Plant VOCs are signaling compounds that attract pollinators, protect plants from stress, disease ... more Plant VOCs are signaling compounds that attract pollinators, protect plants from stress, disease and predation, have allelopathic effects and play a role in plant growth and development. The purpose of this review was to evaluate pollinator plants for secondary metabolite VOCs such as monoterpenes and sesquiterpenes for their potential medicinal value to pollinating insects. To address disease pathogens impacting native pollinators and honeybees, plants with medicinal VOCs can be selected for prairie strips and pollinator gardens as agricultural best management practices. Eight flowering plants - bee balm, echinacea, catmint, prairie rose, lavender, thyme, oregano and red clover contain VOCs in their nectars and pollens such as caryophyllene, myrcene, germacrene, cymene, thymol, cineol, carvacrol, borneol, nonanal, linalool and terpineol that offer antimicrobial, antifungal, anti-inflammatory, antioxidant benefits and some are acaricides that may aid in controlling the Varroa destru...

The toxicity of three PCB congeners having different structural characteristics was studied using... more The toxicity of three PCB congeners having different structural characteristics was studied using water exposures and the embryos of two sea urchin species, Strongylocentrotus purpuratus (purple sea urchin) and Lytechinus pictus (white sea urchin). Biological effects were assessed using two endpoints: percentage of normal embryo development and mitotic rate. Differential toxicity of the congeners was observed, with Congener 47 producing much stronger effects than Congeners 77 and 153 at comparable body burdens. The effects of PCBs on embryo development were similar in both species investigated. It was found that mitotic rate measurement was a more sensitive indicator of effects than was embryo development. The results of this study illustrate that different PCB congener structure activity relationships exist for various animal groups and/or endpoints. Widely used estimates of congener relative toxicity derived from mammalian research are not accurate for estimating effects on marine...

Water Science and Technology

A malodorous chemical, 2-ethyl-5,5′-dimethyl-1,3-dioxane (2EDD) created a drinking water taste an... more A malodorous chemical, 2-ethyl-5,5′-dimethyl-1,3-dioxane (2EDD) created a drinking water taste and odor episode in Pennsylvania (USA) during 1992. The odor episode occurred as the result of a reaction between propionaldehyde and neopentyl glycol in the waste tank of a resin manufacturer. Samples of this waste water were extracted and analyzed. An in situ aqueous preparation of 2EDD was completed to demonstrate that 2EDD could have formed under the conditions found in the waste water. The stability (fate) of 2EDD was studied at different aqueous pHs (pH3, 5, 7, and 9). Some hydrolysis of 2EDD was found at pHs<7 after one week, but 2EDD appeared to be stable at pH 9. The odor characteristics and odor threshold of 2EDD were determined by the method of flavor profile analysis. The odor threshold concentration of 2EDD was found to be between 5 and 10 ng/l and was described as having a sweet, tutti fruitti odor (near the odor threshold concentration) and a burnt, sickening sweet odor a...

Ecotoxicology and environmental safety, Jan 11, 2017

The impacts of air emissions as a consequence of industrial activities around communities of huma... more The impacts of air emissions as a consequence of industrial activities around communities of human habitation have been extensively reported. This study is the first to assess potential adverse human health effects in the Chemical Valley Sarnia (CVS) area, around the St. Clair River, using health risk models, ecological and pollution indices. Large quantities of particulate matters (PM) are generated from anthropogenic activities, which contain several heavy metals in trace quantities with potentially adverse effects to humans and environmental health. The distribution, and human health impact assessment of trace element concentrations in PM fractions were examined. Elemental concentrations of As, Cd, Cr (VI), Cu, Fe, Mn, Pb, Ni, Zn were determined in the PM size-segregated samples collected from the CVS area between 2014 and 2017. The results showed relatively high concentration of PM<2.5 (87.19±8.1(mgm(3))) which is approximately 4 times the WHO air quality guidelines. Pb conce...

Water science and technology : a journal of the International Association on Water Pollution Research, 2004

In order to assist drinking water utilities with identifying the possible sources and causes of t... more In order to assist drinking water utilities with identifying the possible sources and causes of taste-and-odor conditions associated with materials used in distribution systems, we evaluated information from case studies and a database from the National Sanitation Foundation (NSF), International. This database identified chemicals that had leached from drinking water system components during testing of materials under ANSI/NSF Standard 61, which provides information to water utilities on potential taste-and-odor and health concerns from the use of new materials. The data were arranged to provide a process for locating the potential source of a taste-and-odor event. After a sensory analysis is conducted on the drinking water samples, the descriptor can be matched with categories on the "Drinking Water Taste and Odor Wheel 2000" in order to suggest the candidate material.

Water Practice and Technology, 2010

The occurrence of 51 pharmaceuticals and personal care products (PPCPs) and endocrine disrupting ... more The occurrence of 51 pharmaceuticals and personal care products (PPCPs) and endocrine disrupting compounds (EDCs) in the Detroit River Watershed (DRW) was investigated. Also, the efficiency of local water treatment plants (WTPs) in removing these pollutants was evaluated. Samples were collected from various locations in the DRW, including the discharge of a sewage treatment plant (STP), downstream of the STP on the Detroit River, the intakes of the WTPs, and treated drinking water. Of the 51 target substances analyzed, 12 were not detected in any of the samples, while 14 were detected consistently in all samples from the STP effluent. The concentration of target chemicals was two to four orders of magnitude higher in the STP effluents than at the intakes of the WTPs. In total, 10 substances were detected in at least 10% of the drinking water samples. Two compounds, perfluorooctanoic acid (PFOA) and perfluorooctyl solfonate (PFOS), were found in 90+% of the drinking water samples.

Water Science & Technology: Water Supply, 2009

Several PPCPs/EDCs are being detected in surface drinking water sources, which is a great concern... more Several PPCPs/EDCs are being detected in surface drinking water sources, which is a great concern. The efficacy of ozonation in oxidizing 13 PPCPs/EDCs frequently detected in the Detroit River watershed was examined at pilot scale in the current study. Pilot-scale experiments ...

Water Science and Technology, 1999

Information OD the toxicity of individual chemicals that have been used as known or representativ... more Information OD the toxicity of individual chemicals that have been used as known or representative odor standards in the method of Flavor Profile Analysis (FPA) was compiled for an exposure assessment. A full risk assessment was not possible since unit risk values for most of these chemicals do not exist. This study provides a recommendation as to what chemicals can be safely used as known and representat ive taste and odor standards for the next modification of the Flavor Profile:Analysis Standard Method 2170. Excluding any potential odor standard listed as possible or probable earcmogens, there would be no known risk to FPA panelists being exposed to the selected odor reference chemicals at the concentrations used in FPA. Also, the concentrations which panelists are exposed to during an FPA (20 minutes per chemical) are lower than the legal threshold limit values for 8 hour occupational exposures. However, many of the odor reference chemicals have yet to be evaluated for their carcinogenic or noncarcinogenic endpoints. Recommendations are made as to which chemicals should be avoided.

Water Science and Technology - WATER SCI TECHNOL, 1999

Information OD the toxicity of individual chemicals that have been used as known or representativ... more Information OD the toxicity of individual chemicals that have been used as known or representative odor standards in the method of Flavor Profile Analysis (FPA) was compiled for an exposure assessment. A full risk assessment was not possible since unit risk values for most of these chemicals do not exist. This study provides a recommendation as to what chemicals can be safely used as known and representat ive taste and odor standards for the next modification of the Flavor Profile:Analysis Standard Method 2170. Excluding any potential odor standard listed as possible or probable earcmogens, there would be no known risk to FPA panelists being exposed to the selected odor reference chemicals at the concentrations used in FPA. Also, the concentrations which panelists are exposed to during an FPA (20 minutes per chemical) are lower than the legal threshold limit values for 8 hour occupational exposures. However, many of the odor reference chemicals have yet to be evaluated for their carcinogenic or noncarcinogenic endpoints. Recommendations are made as to which chemicals should be avoided.

Ozone: Science & Engineering, 2006

Reports by different scientific groups indicate concern about traces of drugs that could make the... more Reports by different scientific groups indicate concern about traces of drugs that could make their way into tap water. Studies indicate that activated carbon and ozone are promising treatment methods to remove traces of pharmaceuticals and pesticides. The Windsor Utilities Commission (WUC), Windsor, Ontario, Canada, evaluated the occurrence of pharmaceuticals and endocrine disrupting chemicals in its raw water supply, and the effectiveness of ozone in removing these compounds. The analysis indicated that trace levels of compounds such as carbamazepine, caffeine, cotinine, and atrazine were detected in raw water and that treatment with ozone resulted in a greater removal versus conventional treatment.

Ozone: Science & Engineering, 2008

The application of pre-coagulation ozone in drinking water treatment to provide primary disinfect... more The application of pre-coagulation ozone in drinking water treatment to provide primary disinfection, has an impact on coagulation and flocculation, and needs to be evaluated further for cold water temperatures, especially when accompanied by episodes of high alkalinity and dissolved organic carbon (DOC). Ozone application to raw water, prior to the addition of coagulants and coagulant aides, was shown to reduce coagulant and coagulant aide doses, and improve settled and filtered water turbidity. The impact on particle count was also noticeable, filtered water particle count was reduced after the application of pre-coagulation ozonation. Pilotscale experiments were conducted at the Walkerton Clean Water Centre, Walkerton, Ontario, Canada, to investigate the effect of pre-coagulation ozonation, on filtered water turbidity, particle count, and filter performance, during periods when water temperatures could be lower than 5 C.

Water Science and Technology - WATER SCI TECHNOL, 1999

A malodorous chemical, 2-elhyl-S,S'-dimethyl•I,3-dioxane(2EDD) created I drinking Wiler taste and... more A malodorous chemical, 2-elhyl-S,S'-dimethyl•I,3-dioxane(2EDD) created I drinking Wiler taste and odor episode in Pennsylvania (USA) during 1992. The odor episode occurred as the result of I reaction between propionaldehyde and neopentyl glycol in the waste tank ofa resin manufacturer. Samples of this waste water were extracted and analyzed. An in situ aqueous preparation of 2EDD was I:ompleted to demonstrate thaI 2EDD could have formed under the conditions found in the waste water. The stability (fate) of 2EDD was studied at different aqueous pHs (pH3, S, 7, and 9). Some hydrolysis of2EDD was found at pHs<7 after one week, but 2EDD appeared to be stable at pH 9. The odor characteristics and odor threshold of 2EDD were determined by the method of flavor profile analysis. The odor threshold concentrationof 2EDD was found to be between 5 and to ngll and was described IS having a sweet, tutti fruitti odor (near the odor threshold concentration) and a burnt, sil:kening sweet odor at higher concentrations. This study also discovered that slight antagonism in chloraminateddrinking water may occur at or near the threshold odor level of 2£OD.

Marine Environmental Research, 2003

We tested whether the growth rates of small benthic fish (Gillichthys mirabilis) in three souther... more We tested whether the growth rates of small benthic fish (Gillichthys mirabilis) in three southern California estuaries corresponded with the local concentrations of contaminants. Fish originating from each estuary were transplanted to cages in each estuary in two reciprocal transplant experiments. The growth rates of caged fish, and the size-distribution of natural populations, showed the same pattern of difference among estuaries. Twelve metals and organic contaminants occurred in bulk sediments at concentrations close to their individual ERL values, and a simple index of their combined concentration (the mean ERL quotient) was inversely correlated to the growth of caged fish. Metals in the water column occurred at lower concentrations, relative to toxicity thresholds, than those in sediments and were unrelated to fish growth. Fish used in the field caging experiments, and other fish held in the laboratory under constant conditions, showed no difference in growth according to their

Limnology and Oceanography, 2008

Riverine water samples (dissolved and particulate), surficial bottom sediments, and trapped sedim... more Riverine water samples (dissolved and particulate), surficial bottom sediments, and trapped sediments were collected mostly monthly from three stations along the Clinton River, in southeastern Michigan, over a period of ,1 yr and analyzed for 7 Be and 210 Pb to elucidate the types and rates of processes affecting particle dynamics in a riverine system. Using a simple irreversible scavenging box model approach, sources and sinks for dissolved and particulate 7 Be and 210 Pb were quantified to estimate their residence times in the dissolved and particulate phases. Resuspension rates of surficial bottom sediments calculated from the mass balance of particulate 7 Be varied from 0.50 to 1.34 (geometric mean: 0.83 6 0.34) g cm 22 yr 21 , while corresponding values varied from 0.16 to 1.48 (GM: 0.38 6 0.38) g cm 22 yr 21 using particulate 210 Pb. Based on the 210 Pb mass balance, it appears that only ,2% of 210 Pb was derived from direct atmospheric deposition, while ,98% was derived from resuspension of bottom sediments. Additionally, there was a large discrepancy between mass flux collected in the trap (GM: 8.9 g cm 22 yr 21) compared to net sediment accumulation rates (GM: 0.88 6 0.38 g cm 22 yr 21), which was attributed to sediment resuspension; this may provide insight into the frequency of particle-recycling events. Furthermore, desorption of particle-reactive species during resuspension events could result in the mobility of contaminants to farther distances from the contaminated site. Therefore, this study has direct relevance to the uptake of particle-reactive species in a riverine system and thereby the water quality of rivers.

Journal of Great Lakes Research, 2010

The Clinton River watershed near Detroit, Michigan, USA was separated in six different land uses:... more The Clinton River watershed near Detroit, Michigan, USA was separated in six different land uses: agricultural, residential, mixed industrial and residential, downstream industrial, Clinton River Spillway, and Lake St. Clair, utilizing As, Cd, Cu, Ni, Pb, and Zn contents of the sediment that has median values of 3, 0.3, 15, 14, 13, and 57 mg kg − 1 , respectively. However, trace element concentrations in the lower Clinton River rivaled those in the most contaminated watersheds of the world. Enrichment factors and principal component analysis (PCA) separated trace elements into 2 categories: anthropogenic (Cd, Cu, Ni, Pb, and Zn) and geogenic (Al, As, Ca, Fe, K, Mg, TOC) sources. PCA linked agricultural, residential, and mixed industrial and residential land uses to anthropogenic Cd, Cu, Ni, Pb, and Zn, and lake sediments to geogenic elements, organic matter and clay contents. The downstream industrial zone has a unique source signature. Trace element concentrations varied with land use. The upper Clinton River (N 20 km from mouth; residential land use; median concentrations up to 25 mg kg − 1) appeared to meet delisting criteria. Partitioning was also land use and element specific with: (1) exchangeable fraction (up to 94% of total) related to road salt and mobile chloride complex formation; (2) carbonate-bound fraction (up to 100%) resulting from Ca substitution or adsorption; (3) presence of immobile (hydr)oxide-bound fraction (up to 90%) instead of potentially mobile organic matter and sulphide-bound fraction (up to 20%); and (4) residual fraction (up to 65%) originating from geogenic and/or anthropogenic sources. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.

Water Science and Technology, 2004

A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, ... more A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, 2001 for the purpose of developing a method for testing drinking water system components for their potential to contribute to taste-and-odor problems in drinking water. The workshop participants derived a method using provisions from European Standards as well as newly developed approaches. It is intended that this method can serve as a temporary procedure for water utilities, as well as a recommended template to derive an official standard. Materials to be tested may include pipes, fittings, ancillaries, joints, lubricants, tanks, and reservoirs. The recommended method includes a migration (leaching) test with chlorinated water, followed by sensory analysis of the samples from the migration test after dechlorination. Sensory analyses use both statistical (e.g., triangle test) and descriptive (e.g. Flavor Profile Analysis) techniques. A decision tree for the results is provided.

Environmental Toxicology and Chemistry, 2000

The dietary assimilation of a polychlorinated biphenyl (PCB) in adult sea urchins and the effects... more The dietary assimilation of a polychlorinated biphenyl (PCB) in adult sea urchins and the effects of maternal transfer of the PCB on sea urchin offspring were investigated and compared to an earlier study where this PCB produced toxicity to developing sea urchin embryos exposed directly through the water route. Adult sea urchins were allowed to graze on sediment spiked with radiolabeled PCB, 2,2′,4,4′‐tetrachlorobiphenyl, for 35 days. The sea urchin L. pictus was found to have a high pollutant extraction efficiency; approx. 62% of the bulk PCB sediment concentration is removed while passing through the gut. Maternal transfer of PCB 2,2′,4,4′‐tetrachlorobiphenyl did not prove to be a more sensitive exposure route to developing embryos than the direct water route. Both adult sea urchins and their offspring were found to be resilient to the effects of this PCB at environmentally relevant sediment concentrations and at levels expected on the basis of the critical body residue theory or ...

The effects of maternal transfer of polychlorinated biphenyl (PCB) Congener 47 on sea urchin offs... more The effects of maternal transfer of polychlorinated biphenyl (PCB) Congener 47 on sea urchin offspring were investigated and compared to the toxicity produced by exposure of sea urchin embryos to this PCB dissolved in seawater. Adult sea urchins were exposed to sediments spiked with the PCB Congener 47 (2,2’,4,4’tetrachlorobiphenyl) at concentrations of 0, 0.5, 5, and 20 mg/kg dry wt. The sea urchins were spawned after a 35-d exposure to the PCB, and the embryos were measured for bioaccumulation and toxic effects. Toxicity was also evaluated in adult sea urchins by measuring growth rate and gonadal somatic index (GSI, percent of weight which is gonad) at the different doses. Maternal transfer of Congener 47 was substantial, approximately 30% of the mass of PCB in adults was contained within eggs. No toxic effects were detected in the PCB-exposed embryos or adults. The results of this experiment indicate that sea urchin embryos exposed to PCB from maternal transfer are no more sensit...

Plant VOCs are signaling compounds that attract pollinators, protect plants from stress, disease ... more Plant VOCs are signaling compounds that attract pollinators, protect plants from stress, disease and predation, have allelopathic effects and play a role in plant growth and development. The purpose of this review was to evaluate pollinator plants for secondary metabolite VOCs such as monoterpenes and sesquiterpenes for their potential medicinal value to pollinating insects. To address disease pathogens impacting native pollinators and honeybees, plants with medicinal VOCs can be selected for prairie strips and pollinator gardens as agricultural best management practices. Eight flowering plants - bee balm, echinacea, catmint, prairie rose, lavender, thyme, oregano and red clover contain VOCs in their nectars and pollens such as caryophyllene, myrcene, germacrene, cymene, thymol, cineol, carvacrol, borneol, nonanal, linalool and terpineol that offer antimicrobial, antifungal, anti-inflammatory, antioxidant benefits and some are acaricides that may aid in controlling the Varroa destru...

The toxicity of three PCB congeners having different structural characteristics was studied using... more The toxicity of three PCB congeners having different structural characteristics was studied using water exposures and the embryos of two sea urchin species, Strongylocentrotus purpuratus (purple sea urchin) and Lytechinus pictus (white sea urchin). Biological effects were assessed using two endpoints: percentage of normal embryo development and mitotic rate. Differential toxicity of the congeners was observed, with Congener 47 producing much stronger effects than Congeners 77 and 153 at comparable body burdens. The effects of PCBs on embryo development were similar in both species investigated. It was found that mitotic rate measurement was a more sensitive indicator of effects than was embryo development. The results of this study illustrate that different PCB congener structure activity relationships exist for various animal groups and/or endpoints. Widely used estimates of congener relative toxicity derived from mammalian research are not accurate for estimating effects on marine...

Water Science and Technology

A malodorous chemical, 2-ethyl-5,5′-dimethyl-1,3-dioxane (2EDD) created a drinking water taste an... more A malodorous chemical, 2-ethyl-5,5′-dimethyl-1,3-dioxane (2EDD) created a drinking water taste and odor episode in Pennsylvania (USA) during 1992. The odor episode occurred as the result of a reaction between propionaldehyde and neopentyl glycol in the waste tank of a resin manufacturer. Samples of this waste water were extracted and analyzed. An in situ aqueous preparation of 2EDD was completed to demonstrate that 2EDD could have formed under the conditions found in the waste water. The stability (fate) of 2EDD was studied at different aqueous pHs (pH3, 5, 7, and 9). Some hydrolysis of 2EDD was found at pHs<7 after one week, but 2EDD appeared to be stable at pH 9. The odor characteristics and odor threshold of 2EDD were determined by the method of flavor profile analysis. The odor threshold concentration of 2EDD was found to be between 5 and 10 ng/l and was described as having a sweet, tutti fruitti odor (near the odor threshold concentration) and a burnt, sickening sweet odor a...

Ecotoxicology and environmental safety, Jan 11, 2017

The impacts of air emissions as a consequence of industrial activities around communities of huma... more The impacts of air emissions as a consequence of industrial activities around communities of human habitation have been extensively reported. This study is the first to assess potential adverse human health effects in the Chemical Valley Sarnia (CVS) area, around the St. Clair River, using health risk models, ecological and pollution indices. Large quantities of particulate matters (PM) are generated from anthropogenic activities, which contain several heavy metals in trace quantities with potentially adverse effects to humans and environmental health. The distribution, and human health impact assessment of trace element concentrations in PM fractions were examined. Elemental concentrations of As, Cd, Cr (VI), Cu, Fe, Mn, Pb, Ni, Zn were determined in the PM size-segregated samples collected from the CVS area between 2014 and 2017. The results showed relatively high concentration of PM<2.5 (87.19±8.1(mgm(3))) which is approximately 4 times the WHO air quality guidelines. Pb conce...

Water science and technology : a journal of the International Association on Water Pollution Research, 2004

In order to assist drinking water utilities with identifying the possible sources and causes of t... more In order to assist drinking water utilities with identifying the possible sources and causes of taste-and-odor conditions associated with materials used in distribution systems, we evaluated information from case studies and a database from the National Sanitation Foundation (NSF), International. This database identified chemicals that had leached from drinking water system components during testing of materials under ANSI/NSF Standard 61, which provides information to water utilities on potential taste-and-odor and health concerns from the use of new materials. The data were arranged to provide a process for locating the potential source of a taste-and-odor event. After a sensory analysis is conducted on the drinking water samples, the descriptor can be matched with categories on the "Drinking Water Taste and Odor Wheel 2000" in order to suggest the candidate material.

Water Practice and Technology, 2010

The occurrence of 51 pharmaceuticals and personal care products (PPCPs) and endocrine disrupting ... more The occurrence of 51 pharmaceuticals and personal care products (PPCPs) and endocrine disrupting compounds (EDCs) in the Detroit River Watershed (DRW) was investigated. Also, the efficiency of local water treatment plants (WTPs) in removing these pollutants was evaluated. Samples were collected from various locations in the DRW, including the discharge of a sewage treatment plant (STP), downstream of the STP on the Detroit River, the intakes of the WTPs, and treated drinking water. Of the 51 target substances analyzed, 12 were not detected in any of the samples, while 14 were detected consistently in all samples from the STP effluent. The concentration of target chemicals was two to four orders of magnitude higher in the STP effluents than at the intakes of the WTPs. In total, 10 substances were detected in at least 10% of the drinking water samples. Two compounds, perfluorooctanoic acid (PFOA) and perfluorooctyl solfonate (PFOS), were found in 90+% of the drinking water samples.

Water Science & Technology: Water Supply, 2009

Several PPCPs/EDCs are being detected in surface drinking water sources, which is a great concern... more Several PPCPs/EDCs are being detected in surface drinking water sources, which is a great concern. The efficacy of ozonation in oxidizing 13 PPCPs/EDCs frequently detected in the Detroit River watershed was examined at pilot scale in the current study. Pilot-scale experiments ...

Water Science and Technology, 1999

Information OD the toxicity of individual chemicals that have been used as known or representativ... more Information OD the toxicity of individual chemicals that have been used as known or representative odor standards in the method of Flavor Profile Analysis (FPA) was compiled for an exposure assessment. A full risk assessment was not possible since unit risk values for most of these chemicals do not exist. This study provides a recommendation as to what chemicals can be safely used as known and representat ive taste and odor standards for the next modification of the Flavor Profile:Analysis Standard Method 2170. Excluding any potential odor standard listed as possible or probable earcmogens, there would be no known risk to FPA panelists being exposed to the selected odor reference chemicals at the concentrations used in FPA. Also, the concentrations which panelists are exposed to during an FPA (20 minutes per chemical) are lower than the legal threshold limit values for 8 hour occupational exposures. However, many of the odor reference chemicals have yet to be evaluated for their carcinogenic or noncarcinogenic endpoints. Recommendations are made as to which chemicals should be avoided.

Water Science and Technology - WATER SCI TECHNOL, 1999

Information OD the toxicity of individual chemicals that have been used as known or representativ... more Information OD the toxicity of individual chemicals that have been used as known or representative odor standards in the method of Flavor Profile Analysis (FPA) was compiled for an exposure assessment. A full risk assessment was not possible since unit risk values for most of these chemicals do not exist. This study provides a recommendation as to what chemicals can be safely used as known and representat ive taste and odor standards for the next modification of the Flavor Profile:Analysis Standard Method 2170. Excluding any potential odor standard listed as possible or probable earcmogens, there would be no known risk to FPA panelists being exposed to the selected odor reference chemicals at the concentrations used in FPA. Also, the concentrations which panelists are exposed to during an FPA (20 minutes per chemical) are lower than the legal threshold limit values for 8 hour occupational exposures. However, many of the odor reference chemicals have yet to be evaluated for their carcinogenic or noncarcinogenic endpoints. Recommendations are made as to which chemicals should be avoided.

Ozone: Science & Engineering, 2006

Reports by different scientific groups indicate concern about traces of drugs that could make the... more Reports by different scientific groups indicate concern about traces of drugs that could make their way into tap water. Studies indicate that activated carbon and ozone are promising treatment methods to remove traces of pharmaceuticals and pesticides. The Windsor Utilities Commission (WUC), Windsor, Ontario, Canada, evaluated the occurrence of pharmaceuticals and endocrine disrupting chemicals in its raw water supply, and the effectiveness of ozone in removing these compounds. The analysis indicated that trace levels of compounds such as carbamazepine, caffeine, cotinine, and atrazine were detected in raw water and that treatment with ozone resulted in a greater removal versus conventional treatment.

Ozone: Science & Engineering, 2008

The application of pre-coagulation ozone in drinking water treatment to provide primary disinfect... more The application of pre-coagulation ozone in drinking water treatment to provide primary disinfection, has an impact on coagulation and flocculation, and needs to be evaluated further for cold water temperatures, especially when accompanied by episodes of high alkalinity and dissolved organic carbon (DOC). Ozone application to raw water, prior to the addition of coagulants and coagulant aides, was shown to reduce coagulant and coagulant aide doses, and improve settled and filtered water turbidity. The impact on particle count was also noticeable, filtered water particle count was reduced after the application of pre-coagulation ozonation. Pilotscale experiments were conducted at the Walkerton Clean Water Centre, Walkerton, Ontario, Canada, to investigate the effect of pre-coagulation ozonation, on filtered water turbidity, particle count, and filter performance, during periods when water temperatures could be lower than 5 C.

Water Science and Technology - WATER SCI TECHNOL, 1999

A malodorous chemical, 2-elhyl-S,S'-dimethyl•I,3-dioxane(2EDD) created I drinking Wiler taste and... more A malodorous chemical, 2-elhyl-S,S'-dimethyl•I,3-dioxane(2EDD) created I drinking Wiler taste and odor episode in Pennsylvania (USA) during 1992. The odor episode occurred as the result of I reaction between propionaldehyde and neopentyl glycol in the waste tank ofa resin manufacturer. Samples of this waste water were extracted and analyzed. An in situ aqueous preparation of 2EDD was I:ompleted to demonstrate thaI 2EDD could have formed under the conditions found in the waste water. The stability (fate) of 2EDD was studied at different aqueous pHs (pH3, S, 7, and 9). Some hydrolysis of2EDD was found at pHs<7 after one week, but 2EDD appeared to be stable at pH 9. The odor characteristics and odor threshold of 2EDD were determined by the method of flavor profile analysis. The odor threshold concentrationof 2EDD was found to be between 5 and to ngll and was described IS having a sweet, tutti fruitti odor (near the odor threshold concentration) and a burnt, sil:kening sweet odor at higher concentrations. This study also discovered that slight antagonism in chloraminateddrinking water may occur at or near the threshold odor level of 2£OD.

Marine Environmental Research, 2003

We tested whether the growth rates of small benthic fish (Gillichthys mirabilis) in three souther... more We tested whether the growth rates of small benthic fish (Gillichthys mirabilis) in three southern California estuaries corresponded with the local concentrations of contaminants. Fish originating from each estuary were transplanted to cages in each estuary in two reciprocal transplant experiments. The growth rates of caged fish, and the size-distribution of natural populations, showed the same pattern of difference among estuaries. Twelve metals and organic contaminants occurred in bulk sediments at concentrations close to their individual ERL values, and a simple index of their combined concentration (the mean ERL quotient) was inversely correlated to the growth of caged fish. Metals in the water column occurred at lower concentrations, relative to toxicity thresholds, than those in sediments and were unrelated to fish growth. Fish used in the field caging experiments, and other fish held in the laboratory under constant conditions, showed no difference in growth according to their

Limnology and Oceanography, 2008

Riverine water samples (dissolved and particulate), surficial bottom sediments, and trapped sedim... more Riverine water samples (dissolved and particulate), surficial bottom sediments, and trapped sediments were collected mostly monthly from three stations along the Clinton River, in southeastern Michigan, over a period of ,1 yr and analyzed for 7 Be and 210 Pb to elucidate the types and rates of processes affecting particle dynamics in a riverine system. Using a simple irreversible scavenging box model approach, sources and sinks for dissolved and particulate 7 Be and 210 Pb were quantified to estimate their residence times in the dissolved and particulate phases. Resuspension rates of surficial bottom sediments calculated from the mass balance of particulate 7 Be varied from 0.50 to 1.34 (geometric mean: 0.83 6 0.34) g cm 22 yr 21 , while corresponding values varied from 0.16 to 1.48 (GM: 0.38 6 0.38) g cm 22 yr 21 using particulate 210 Pb. Based on the 210 Pb mass balance, it appears that only ,2% of 210 Pb was derived from direct atmospheric deposition, while ,98% was derived from resuspension of bottom sediments. Additionally, there was a large discrepancy between mass flux collected in the trap (GM: 8.9 g cm 22 yr 21) compared to net sediment accumulation rates (GM: 0.88 6 0.38 g cm 22 yr 21), which was attributed to sediment resuspension; this may provide insight into the frequency of particle-recycling events. Furthermore, desorption of particle-reactive species during resuspension events could result in the mobility of contaminants to farther distances from the contaminated site. Therefore, this study has direct relevance to the uptake of particle-reactive species in a riverine system and thereby the water quality of rivers.

Journal of Great Lakes Research, 2010

The Clinton River watershed near Detroit, Michigan, USA was separated in six different land uses:... more The Clinton River watershed near Detroit, Michigan, USA was separated in six different land uses: agricultural, residential, mixed industrial and residential, downstream industrial, Clinton River Spillway, and Lake St. Clair, utilizing As, Cd, Cu, Ni, Pb, and Zn contents of the sediment that has median values of 3, 0.3, 15, 14, 13, and 57 mg kg − 1 , respectively. However, trace element concentrations in the lower Clinton River rivaled those in the most contaminated watersheds of the world. Enrichment factors and principal component analysis (PCA) separated trace elements into 2 categories: anthropogenic (Cd, Cu, Ni, Pb, and Zn) and geogenic (Al, As, Ca, Fe, K, Mg, TOC) sources. PCA linked agricultural, residential, and mixed industrial and residential land uses to anthropogenic Cd, Cu, Ni, Pb, and Zn, and lake sediments to geogenic elements, organic matter and clay contents. The downstream industrial zone has a unique source signature. Trace element concentrations varied with land use. The upper Clinton River (N 20 km from mouth; residential land use; median concentrations up to 25 mg kg − 1) appeared to meet delisting criteria. Partitioning was also land use and element specific with: (1) exchangeable fraction (up to 94% of total) related to road salt and mobile chloride complex formation; (2) carbonate-bound fraction (up to 100%) resulting from Ca substitution or adsorption; (3) presence of immobile (hydr)oxide-bound fraction (up to 90%) instead of potentially mobile organic matter and sulphide-bound fraction (up to 20%); and (4) residual fraction (up to 65%) originating from geogenic and/or anthropogenic sources. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.