Alkylphenol Ethoxylates Research Articles

Effect of Wastewater Treatment Facility Closure on Endocrine Disrupting Chemicals in a Coastal Plain Stream

Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insight into contaminant persistence, long‐term wastewater impacts, and ecosystem recovery processes. The U.S. Geological Survey assessed the fate of select endocrine disrupting chemicals (EDC) in surface water and streambed sediment one year before and one year after closure of a long‐term WWTF located within the Spirit Creek watershed at Fort Gordon, Georgia. Sample sites included a WWTF‐effluent control located upstream from the outfall, three downstream effluent‐impacted sites located between the outfall and Spirit Lake, and one downstream from the lake's outfall. Prior to closure, the 2.2‐km stream segment downstream from the WWTF outfall was characterized by EDC concentrations significantly higher (α = 0.05) than at the control site; indicating substantial downstream transport and limited in‐stream attenuation of EDC, including pharmaceuticals, estrogens, alkylphenol ethoxylate (APE) metabolites, and organophosphate flame retardants (OPFR). Wastewater‐derived pharmaceutical, APE metabolites, and OPFR compounds were also detected in the outflow of Spirit Lake, indicating the potential for EDC transport to aquatic ecosystems downstream of Fort Gordon under effluent discharge conditions. After the WWTF closure, no significant differences in concentrations or numbers of detected EDC compounds were observed between control and downstream locations. The results indicated EDC pseudo‐persistence under preclosure, continuous supply conditions, with rapid attenuation following WWTF closure. Low concentrations of EDC at the control site throughout the study and comparable concentrations in downstream locations after WWTF closure indicated additional, continuing, upstream contaminant sources within the Spirit Creek watershed. ©2016 Wiley Periodicals, Inc.

Simultaneous quantification of bisphenol A, alkylphenols and alkylphenol ethoxylates in indoor dust by gas chromatography-tandem mass spectrometry and a comparison between two sampling techniques

A method based on gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) was developed for the simultaneous quantitation of BPA, OP, n-NP, NP, NP1EO, and NP2EO in indoor dust.

The Impact of 4-Nonylphenol on the Viability and Hormone Production of Mouse Leydig Cells

Exogenous substances altering the function of the endocrine system and exhibiting adverse health effects on the organism are defined as endocrine disruptors. Nonylphenol is one of the most abundant alkylphenol ethoxylate derivatives, being detected in food products. Diverse studies have classified nonylphenol as hazardous to the health, especially to male reproduction. This in vitro study aimed to examine the effects of 4-nonylphenol on androstenedione and testosterone production as well as on the viability of Leydig cells of NMRI mice. The cells were cultured for 44 h with addition of 0.04; 0.2; 1.0; 2.5 and 5.0 μg/ml of 4-nonylphenol and compared to the control. Quantification of testosterone and androstenedione directly from aliquots of the medium was performed by enzyme-linked immunosorbent assay. Cell viability was measured by the metabolic activity assay for mitochondrial functional activity. Androstenedione production significantly (P < 0.001) increased with 1.0; 2.5 and 5.0 μg/ml 4-nonylphenol. Although cAMP-stimulated testosterone production was not significantly affected by 4-nonylphenol, a tendency to attenuate the level of testosterone in the Leydig cells treated with 2.5 and 5.0 μg/ml 4-nonylphenol was observed. The viability of mouse Leydig cells was slightly increased at the lowest doses of 4-nonylphenol (0.04 and 0.2 μg/ml). We also observed an increase at higher concentrations of the substance (1.0; 2.5 and 5.0 μg/ml), but this increase was not significant. Further investigations are required to establish the biological significance and possible reproductive implications.

Surfactants in aquatic and terrestrial environment: occurrence, behavior, and treatment processes.

Surfactants belong to a group of chemicals that are well known for their cleaning properties. Their excessive use as ingredients in care products (e.g., shampoos, body wash) and in household cleaning products (e.g., dishwashing detergents, laundry detergents, hard-surface cleaners) has led to the discharge of highly contaminated wastewaters in aquatic and terrestrial environment. Once reached in the different environmental compartments (rivers, lakes, soils, and sediments), surfactants can undergo aerobic or anaerobic degradation. The most studied surfactants so far are linear alkylbenzene sulfonate (LAS), quaternary ammonium compounds (QACs), alkylphenol ethoxylate (APEOs), and alcohol ethoxylate (AEOs). Concentrations of surfactants in wastewaters can range between few micrograms to hundreds of milligrams in some cases, while it reaches several grams in sludge used for soil amendments in agricultural areas. Above the legislation standards, surfactants can be toxic to aquatic and terrestrial organisms which make treatment processes necessary before their discharge into the environment. Given this fact, biological and chemical processes should be considered for better surfactants removal. In this review, we investigate several issues with regard to: (1) the toxicity of surfactants in the environment, (2) their behavior in different ecological systems, (3) and the different treatment processes used in wastewater treatment plants in order to reduce the effects of surfactants on living organisms.

A new analytical protocol for the determination of 62 endocrine-disrupting compounds in indoor air

The objective of this study was to develop and validate a new analytical protocol for simultaneous determination of 62 semi-volatile organic compounds in both phases of indoor air. Studied compounds belong to several families: polybrominated diphenyl ethers, polychlorinated biphenyls, hexachlorobenzene, pentachlorobenzene, phthalates, polyaromatic hydrocarbons, parabens, tetrabromobisphenol A, bisphenol A, hexabromocyclododecane, triclosan, alkylphenols, alkylphenol ethoxylates, synthetic musks (galaxolide and tonalide) and pesticides (lindane and cypermethrin). A medium volume sampling system was used to collect simultaneously these endocrine-disrupting compounds (EDCs) from the gaseous and particulate phases. An accelerated solvent extraction method was optimized to obtain all EDCs in a single extract by atmospheric phase. Their extraction from the sorbents and their analysis by liquid and gas chromatography–mass spectrometry (LC/MS/MS, GC/MS and GC/MS/MS) was validated using spiked sorbents (recovery study and analytical uncertainty analysis by fully nested design). The developed protocol achieved low limits of quantification (<0.5ngm−3) and low uncertainty values (<5ngm−3) for all compounds. Once validated, the method was applied to indoor air samples from four locations (a house, an apartment, a day nursery and an office) and compared to literature to confirm its efficiency. All target EDCs were quantified in the samples and were primarily present in the gaseous phase. The major contaminants found in indoor air were, in descending order, phthalates, synthetic musks, alkylphenols and parabens.

An integrated method for the simultaneous determination of alkylphenol ethoxylates and brominated flame retardants in sewage sludge samples by ultrasonic-assisted extraction, solid phase clean-up, and GC-MS analysis

Generally, a major route of alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) to enter the environment is via the wastewater treatment works (WWTW) facilities. Consequently, the levels of APEs and BFRs in sewage sludges may give an indication of the general use and exposure of these compounds. The present study was aimed at an integrated method for the analysis and quantification of APEs and BFRs in sewage sludge from selected wastewater treatment plants. The optimization of the extraction procedure included variation of the amount of extracted biomass, the duration, temperature during sonication as well as type of extraction solvent. Chromatographic determinations of APEs and BFRs were carried out with gas chromatography equipped with mass spectrometry detector after derivatization with heptafluorobutyric anhydride (HFBA). The mean percentage recoveries ranged from 39% to 79% (n=3) for sewage sludge after extracting 5g biomass sludge with hexane: acetone (4:1) at 55°C for 45min in two cycles. The mean concentrations of APEs obtained ranged from<LOQ to 365ngg−1, <LOQ to 166ngg−1, <LOQ to 642ngg−1 while the concentration of BFRs obtained range from<LOQ- 17ngg−1, <LOQ to 163ngg−1, <LOQ to 14ngg−1 for sludge samples from Leeuwkuil, Rietspruit, and Sebokeng, respectively. All compounds, except for nonylphenol (NP), BDE47, and BDE154, were detected from the Rietspruit WWTW. The presence of these pollutants in Rietspruit WWTW may be attributed by the fact that this treatment plants treat wastewater from domestic as well industrial discharges from the surrounding area.

4-Nonylphenol reduces cell viability and induces apoptosis and ER-stress in a human epithelial intestinal cell line

4-Nonylphenol is a widely diffused and stable environmental contaminant, originating from the degradation of alkyl phenol ethoxylates, common surfactants employed in several industrial applications. Due to its hydrophobic nature, 4-nonylphenol can easily accumulate in living organisms, including humans, where it displays a wide range of toxic effects. Since the gastrointestinal tract represents the main route by which 4-nonylphenol enters the body, the intestine may be one of the first organs to be damaged by chronic exposure to this pollutant through the diet. In the present study, we investigated the effects of 4-nonylphenol on a human intestinal epithelial cell line (Caco-2 cells). We demonstrated that 4-nonylphenol was cytotoxic to cells, as revealed by a decrease of the cell number and the decrement of mitochondrial functionality after 24h of treatment. 4-Nonylphenol also reduced the number of cells entering into S-phase and interfered with epidermal growth factor signalling, with consequent negative effects on cell survival. In addition, 4-nonylphenol induced apoptosis, involving the activation of caspase-3, and triggered an endoplasmic reticulum-stress response, as revealed by over-expression of GRP78 (78kDa glucose-regulated protein) and activation of XBP1 (X-box binding protein-1). Together, these findings support the hypothesis that prolonged exposure to 4-nonylphenol through the diet may lead to local damage at the level of intestinal mucosa, with potentially negative consequences for intestinal homeostasis and functionality.

Alkylphenol ethoxylates and brominated flame retardants in water, fish (carp) and sediment samples from the Vaal River, South Africa

Alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) are known to be bio-accumulative, persistent, and endocrine disruptors and can cause adverse health effects in animals and humans. In this study, environmental samples were collected from sites along the Vaal River, South Africa in order to determine the concentrations of APEs and BFRs in water, sediment, and fish samples. The highest concentrations of these pollutants were observed from discharge of the Rietspruit WWTW. Measurable levels of both APEs and BFRs were observed with APEs exhibiting higher concentrations than BFRs in all the matrices. The concentrations observed for APEs and BFRs were as follows: 1.00-3.85 μg/L APEs, 0.09-0.26 μg/L PBDEs, ND- 0.14 PBBs and 0.51-1.77 μg/L HBCD for water samples; 47-63 ng/g lipid APEs, 3.24-12.4 ng/g lipid PBB, 4.63-33 ng/g lipid PBDEs and 10-13 ng/g lipid HBCD for fish; and 40-184 ng/g (wet weight (ww)) APEs, 2.93-5.9 ng/g (ww) PBB, 10-24 ng/g (ww) PBDEs, and 15-52 ng/g (ww) HBCD for sediment samples. The concentrations of APEs and BFRs in water samples were found to be in the range with the results reported in the literature while the concentration in fish and sediment were lower than the concentrations reported in other studies.

Improved derivatization protocol for simultaneous determination of alkylphenol ethoxylates and brominated flame retardants followed by gas chromatography–mass spectrometry analyses

Improved derivatization protocol for simultaneous determination of alkylphenol ethoxylates and brominated flame retardants followed by gas chromatography–mass spectrometry analyses

The UNIFAC model and the partition of alkyl and alkylphenol ethoxylate surfactants in the excess phases of middle phase microemulsions

The partition of non-ionic surfactants between oil and water is an important parameter that influences the performance of surfactant-based separations, the fate of surfactants in the environment, and the absorption by surfactants in living organisms. From a thermodynamics point of view, the partition of surfactants between oil and water can be used as a method to quantify the hydrophilic–lipophilic nature of surfactants and oil. In this work, a group contribution model, the universal functional activity coefficient (UNIFAC) framework, has been modified to fit and predict the partition of alkylphenol, and alkyl ethoxylated surfactants between aqueous and oil phases. To perform such calculations the interaction parameters of an ethoxylate functional group were optimized, including the temperature dependence for functional groups known to form hydrogen bonds (CH2CH2OH2O, OHH2O). The optimization was performed by fitting this modified UNIFAC model to experimental partition coefficient of octylphenol ethoxylated surfactants in the excess phases (water and n-heptane) of middle phase microemulsions at 25 and 55°C and to experimental critical micelle concentration (CMC) data. The modified UNIFAC is capable of predicting the partition of alkylphenol ethoxylates and alkyl ethoxylates with varying degrees of ethoxylation, tail length and temperature and different oils. The predicted partition values correlate with experimental bioconcentration factors (BCFs) reported for alkyl ethoxylates. The model also predicts properly the critical micelle concentration (CMC) of alkyl and alkylphenol ethoxylate surfactants. The predicted partitions also helped estimate the equivalent alkane carbon numbers (EACNs) of various oils.

A Simplified Analytical Procedure for Simultaneous Determination of Alkylphenol Ethoxylates and Brominated Flame Retardants in Fish Tissue Samples from Vaal River, South Africa

In this study, the concentration of alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) were determined in fish samples, Labeo umbratus and Carp, collected from the Vaal River in South Africa. Ultrasonic-assisted extraction technique was used to extract the organic contaminants from fish samples, and the resulting extract was purified by sulphuric acid lipid removal followed by Strata X-cartridge SPE clean-up. The APEs and BFRs were derivatized using heptafluorobutyric anhydride before analysis with GC-MS. In both types of fish samples, lower oligomers of APEs were more abundant than the higher oligomers, while HBCD, BDE99 and PBB101 were the dominant BFRs. The concentrations of these pollutants ranged from 1.061 ng/g lipids (t-BP) in Labeo umbratus to 11.860 ng/g lipids (HBCD) in Carp.

Report on the two‐phase public consultation on the draft EFSA scientific opinion on bisphenol A (BPA)

Report on the two‐phase public consultation on the draft EFSA scientific opinion on bisphenol A (BPA)

Event-based quantification of emerging pollutant removal for an open stormwater retention basin – Loads, efficiency and importance of uncertainties

Up to now, emerging contaminants have not been further-studied in in-situ stormwater best management practices and especially in detention basins. In this article, the efficiency of a dry stormwater detention basin was investigated regarding the removal of 7 alkylphenols and alkylphenol ethoxylates, 9 polybrominated diphenyl ethers, 45 pesticides and bisphenol A. Concentrations of contaminants were obtained by chemical analysis on dissolved and particulate phase distinctly. The removal efficiency was assessed on total, dissolved and particulate phase accounting for the global chain of uncertainty with a 95% confidence interval.Results showed that pesticides (rather hydrophilic) are not trapped in the detention basin but are released contrarily to B209 which is mostly in particulate phase. Alkylphenols and alkylphenol ethoxylates are present in both phases and the efficiency is storm event-dependent.Uncertainty consideration in efficiency determination revealed efficiency data, usually presented by raw values are not relevant to conclude on the performance of a detention basin. In this case study, efficiency data with a 95% confidence interval indicate that only 35%, 50% and 41% of campaigns showed an impact (in trapping or releasing) of the detention basin on alkylphenols and ethoxylates, polybrominated diphenyl ethers and pesticides respectively.

Exploring the impacts of two separate mixtures of pesticide and surfactants on estrogenic activity in male fathead minnows and rainbow trout.

In this study, male fathead minnows (FHM) (Pimephales promelas) and juvenile rainbow trout (RT; Oncorhynchus mykiss) were exposed to two different surfactant mixtures of analytical-grade nonlyphenol, 4-tert octyphenol, octylphenol ethoxylates, nonylphenol ethoxylates, and the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). After a 7-days exposure to environmentally relevant concentrations of these compounds, there was no difference in the relative mRNA expression of vitellogenin (VTG) in male juvenile RT exposed to individual compounds or the 2,4-D-surfactant mixture compared with the control. In male FHM, there was a significant increase in VTG mRNA expression in the high individual treatments of 2,4-D and the surfactants but not the 2,4-D-surfactant mixtures compared with the control. These results were compared with another study exposing male FHM to individual and a mixture of alkylphenols and alkylphenol ethoxylates in two different combinations with the herbicide diuron and the insecticide bifenthrin. There were no differences in the relative expression of VTG mRNA amongst individual exposures and the control. Interestingly, when the ethoxylate mixture was combined with diuron, there was a significant decrease in the relative mRNA expression of VTG compared with the control. However, when the ethoxylate mixture was combined with both diuron and bifenthrin, there was a significant increase in the relative mRNA expression of VTG in male compared with all other groups in the multichemical mixture. The results of this study highlight differences between species and measurements of VTG in assessing the risk of mixtures to aquatic organisms.

Compatibility of nonionic surfactants with membrane materials and their cleaning performance

Membranes applied in industrial processes, such as for the desalination of seawater as well as for dairy and beverage industry are subjected to fouling resulting in a decline of their performance. In order to regain the flux of the membranes, cleaning procedures are conducted, whereby inorganic scale is often removed with acids and organic matter with surfactants under alkaline conditions. Currently, either ionic surfactants or alkylphenol ethoxylates are utilised to clean membranes of organic matter. Other nonionic surfactants (i.e. fatty alcohol ethoxylates) are not applied, due to the assumption that they irreversibly adhere to the membrane surface and thereby clog the pores. At BASF we have studied the adsorption of a wide range of nonionic surfactants to membrane materials. It was shown, that the affinity of nonionic surfactants critically depends on their structure. Linear alkyl ethoxylates irreversibly adsorb to the membrane surfaces, whereas branched alkyl ethoxylates do not. In a second step, we tested the cleaning performance of nonionic surfactants. Similar to the results for adsorption, a structure-performance relationship was discovered where several branched alkyl ethoxylates showed excellent cleaning results. In a third step, combinations of nonionic surfactants, chelating agents and enzymes were tested in terms of cleaning efficiency. All tested combinations showed excellent cleaning performance on bacterial fouling layers.

Dissolution of surfactants in supercritical CO2 with co-solvents

The dissolution of surfactant-like compounds in supercritical CO2 in presence of co-solvents was investigated. The solubility measurement was conducted using a visualized PVT cell combined with UV spectrophotometer method at different pressures and 313K. The viscosity of mixtures of CO2 and co-solvents with or without dissolved surfactants was also measured at similar conditions using a capillary tube rheometer. Nonionic surfactants (N-NP-10c, branched alkylphenol ethoxylates and APG-1214, alkyl polyglucoside) and anionic surfactants (N-NP-15c-H, sulfonated alkylphenol ethoxylates) were studied, which are good CO2 foaming agents. Experimental results showed that increasing pressure and addition of co-solvents could effectively improve solubility of surfactants in supercritical CO2. The addition of ethanol as a co-solvent could increase N-NP-10c's solubility in CO2 from 0.15g (100g)−1 to 1.76g (100g)−1 (over 11 times). APG-1214 with a mixture of ethanol and ethylene glycol as co-solvents exhibited an immediate dissolution capability in CO2, and its solubility could reach up to 1.99g (100g)−1. The solubility of N-NP-15c-H in comparison with APG-1214 was relatively low, only 0.57g (100g)−1 was obtained with the same co-solvents and at similar conditions. The addition of ethanol into CO2 could slightly increase its viscosity, while the effect of ethylene glycol and surfactants was much higher than that of ethanol, which indicates that the dissolution of surfactants in CO2 with co-solvents involves complicated interactions between molecules.

Assessment of Endocrine-Disrupting Chemicals Attenuation in a Coastal Plain Stream Prior to Wastewater Treatment Plant Closure

The U.S. Geological Survey is conducting a combined pre/post-closure assessment at a long-term wastewater treatment plant (WWTP) site at Fort Gordon near Augusta, Georgia. Here, we assess select endocrine-active chemicals and benthic macroinvertebrate community structure prior to closure of the WWTP. Substantial downstream transport and limited instream attenuation of endocrine-disrupting chemicals (EDCs) was observed in Spirit Creek over a 2.2-km stream segment downstream of the WWTP outfall. A modest decline (less than 20% in all cases) in surface water detections was observed with increasing distance downstream of the WWTP and attributed to partitioning to the sediment. Estrogens detected in surface water in this study included estrone (E1), 17β-estradiol (E2), and estriol (E3). The 5 ng/l and higher mean estrogen concentrations observed in downstream locations indicated that the potential for endocrine disruption was substantial. Concentrations of alkylphenol ethoxylate (APE) metabolite EDCs also remained statistically elevated above levels observed at the upstream control site. Wastewater-derived pharmaceutical and APE metabolites were detected in the outflow of Spirit Lake, indicating the potential for EDC transport to aquatic ecosystems downstream of Fort Gordon. The results indicate substantial EDC occurrence, downstream transport, and persistence under continuous supply conditions and provide a baseline for a rare evaluation of ecosystem response to WWTP closure.

Improved derivatization protocol for simultaneous determination of alkylphenol ethoxylates and brominated flame retardants followed by gas chromatography-mass spectrometry analyses.

An improved derivatization protocol for the simultaneous determination of alkylphenol ethoxylates and brominated flame retardants with heptafluorobutyric anhydride under triethylamine amine base was investigated. The derivatization reaction was completed in 30 min at 50 °C using hexane as solvent. Under these conditions, it was observed that alkylphenol ethoxylates and tetrabromobisphenol A were derivatized successfully in the presence of hexabromocyclododecane, lower congeners of polybrominated biphenyls and polybrominated diphenyl ethers. The improved protocol was applied to the recover of the analytes of interest from a simulated water sample after solid phase extraction. The recoveries achieved were above 60%. The limit of detection and limit of quantification ranged from 0.01-0.20 and 0.05-0.66 μg L(-1), respectively. The improved derivatization procedure was also successfully applied to determine trace amounts of these compounds in environmental water samples. The concentrations of the targeted analytes from the environmental samples were determined from limit of quantification. The levels of the targeted compounds in the environmental samples ranged from nd-7.63 ±2.83 μg L(-1).

Occurrence of eight household micropollutants in urban wastewater and their fate in a wastewater treatment plant. Statistical evaluation

The occurrence in urban wastewater of eight micropollutants (erythromycin, ibuprofen, 4-nonylphenol (4-NP), ofloxacin, sucralose, triclosan, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)) originating from household activities and their fate in a biological wastewater treatment plant (WWTP) were investigated. Their concentrations were assessed in the liquid and solid phases (sewage particulate matter and wasted activated sludge (WAS)) by liquid chromatography–tandem mass spectrometry.The analysis of sewage from two different urban catchments connected to the WWTP showed a specific use of ofloxacin in the mixed catchment due to the presence of a hospital, and higher concentrations of sucralose in the residential area.The WWTP process removed over 90% of ibuprofen and triclosan from wastewater, while only 25% of ofloxacin was eliminated. Erythromycin, sucralose and PFOA were not removed from wastewater, the influent and effluent concentrations remaining at about 0.7μg/L, 3μg/L and 10ng/L respectively. The behavior of PFOS and 4-nonylphenol was singular, as concentrations were higher at the WWTP outlet than at its inlet. This was probably related to the degradation of some of their precursors (such as alkylphenol ethoxylates and polyfluorinated compounds resulting in 4-NP and PFOS, respectively) during biological treatment.4-NP, ofloxacin, triclosan and perfluorinated compounds were found adsorbed on WAS (from 5ng/kg for PFOA to 1.0mg/kg for triclosan).The statistical methods (principal component analysis and multiple linear regressions) were applied to examine relationships among the concentrations of micropollutants and macropollutants (COD, ammonium, turbidity) entering and leaving the WWTP. A strong relationship with ammonium indicated that some micropollutants enter wastewater via human urine. A statistical analysis of WWTP operation gave a model for estimating micropollutant output from the WWTP based on a measurement of macropollution parameters.

Determination of nonylphenol ethoxylate and octylphenol ethoxylate surfactants in beehive samples by high performance liquid chromatography coupled to mass spectrometry

Nonylphenol and octylphenol ethoxylates (NP(EO)n and OP(EO)n) are major toxicants in agrochemicals used around beehives. Here we developed a LC–MS method for analysis of NP(EO)3–13 and OP(EO)3–13 oligomers in bee hive matrices. Less than 2 g of honey, pollen or wax were extracted using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach. Recoveries for each oligomer in all matrices are between 75% and 111% at three spiked concentrations. The method proved to be rapid, precise and sensitive. Five honey, 10 pollen and 12 wax samples were collected and analysed. NP(EO)n was detected in every sample with concentrations ranging from 26ppb to 10,239ppb. Much higher NP(EO)n residues levels were found in wax followed by pollen than in honey. OP(EO)n concentrations on average were more than 10 times lower in pollen and wax. This method demonstrates a probable wide occurrence of alkylphenol ethoxylates in USA beehives.