The levels and relative proportions of 11 organophosphorus flame retardants and plasticizers (OPs), some of which are reportedly toxic to aquatic organisms, were investigated in human breast milk and samples of fish and mussels from Swedish lakes and coastal areas in order to assess spatial differences in environmental exposure and spatial and temporal differences in human exposure Some of the biota samples were collected at locations with known potential sources of OPs, but most were collected in background locations Tris-2-chloroisopropyl phosphate (TCPP) and triphenyl phosphate (TPP) dominated in the biota with levels ranging from 170 to 770 ng g−1 for TCPP in perch and between 21 and 180 ng g−1 for TPP In milk samples, TCPP (median 45 ng g−1) and tributyl phosphate (median 12 ng g−1) were the most frequently occurring OPs Among samples of fish from background locations, the concentrations and profiles of most OPs were quite similar, indicating that their sources were diffuse However, in fish from sample locations near known sources, there were marked differences in OP concentrations and profiles Fish from a stream receiving surface water from Arlanda airport displayed high levels of OPs (10 200 ng g−1) that are commonly used in aircraft hydraulic fluids Fish collected at points 1 or 2 km downstream of sewage treatment plants showed significantly higher levels of tris(2-butoxyethyl) phosphate (TBEP), one of the most typically abundant OP in effluents from such plants In the milk samples obtained from women in different towns no distinct differences were detected in OP concentrations or profiles However, the levels of TBEP tended to be higher in milk collected 10 years ago than in milk collected more recently However, human exposure to OPs through eating fish or to breastfeeding babies seems to be of minor importance in relation to other potential sources, such as indoor dust inhalation and ingestion

Organophosphorus flame retardants and plasticizers in marine and fresh water biota and in human milk

Environmental chemistry of phosphonates.

Organophosphonates: A review on environmental relevance, biodegradability and removal in wastewater treatment plants.

Although the ubiquitous distribution of organophosphate esters (OPEs) in the environment has been documented very thoroughly, data on their occurrence in soil is so far sparse. In this study, an analytical method was developed to determine six OPEs in soil. The method consists of a combination of Twisselmann extraction and solid-phase microextraction (SPME), followed by gas chromatography-mass spectrometry (GC-MS). To develop the method, spiked soil was extracted using a Twisselmann extractor after freeze-drying. The extract was evaporated to dryness, redissolved, and filtered. A volume of 7 mL was then analyzed by SPME, followed by GC-MS. The effects of different parameters on analyte recoveries during sample preparation, e.g., solvent for Twisselmann extraction, solvent for redissolving the extract, addition of copper, and filtration of the extract, were systematically investigated. Under optimum conditions, 10 g soil samples were extracted using toluene, and the extract was redissolved in methanol/water (1:14) and filtered. It was not necessary to add copper. For TnBP, TBEP, TCPP, and TCEP, recoveries ranged from 77.0% to 89.6%. Those for TPP and TDCP were much lower, at 31.5% and 42.0%, respectively (addition level 22.9-45.8 ng g(-1)). The variability of recoveries under these conditions was between 0.3 and 16.2% (n = 3). Limits of detection (LOD) were 0.002-3 ng g(-1). When ultrasonication was used in place of Twisselmann extraction in the developed method, recoveries were three to four times lower (27.4% to 30.6%), but the variability of recoveries was below 3% (n = 3). The method was applied to quantify OPEs in soil collected from the university campus in Osnabrueck (Germany). Average concentrations (n = 6) in soil samples ranged from 1.23 ng g(-1) to 4.96 ng g(-1) (dry weight) for TCPP, TPP, and TCEP. The results demonstrate for the first time that atmospheric deposition leads to soil contamination by OPEs.

Application of Twisselmann extraction, SPME, and GC-MS to assess input sources for organophosphate esters into soil.

Phosphonates are to be removed from industrial wastewater before they reach municipal wastewater treatment plants or surface waters. Industrial wastewaters contaminated with the phosphonates 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), 1-hydroxyethylidene-(1,1-diphosphonic acid) (HEDP), nitrilotrimethylphosphonic acid (NTMP), ethylenediamine tetra(methylene phosphonic acid) (EDTMP) and diethylenetriamine penta(methylene phosphonic acid) (DTPMP) can be subdivided into: (1) mostly clear concentrates with a high water hardness, and (2) organically polluted wastewaters, for instance from the paper and textile industries. Our own flocculation experiments with FeIII and AlIII salts showed that, at a pH of 7.5, the adsorption affinity of polyphosphonates onto iron hydroxides and aluminum hydroxides significantly decreases with an increasing number of C-P bonds (HEDP > NTMP > EDTMP > DTPMP). In comparison to pure water spiked with phosphonates, the total P removal from concentrates occurred at similar and even lower flocculant dosage concentrations (s = 4–8) (s is the molar ratio of dosed metal concentration to total P concentration in the raw sample). In organically polluted industrial wastewaters, the formation of flocks, and therefore the total P decrease, only occurred after exceeding a certain flocculant concentration, which varied strongly depending on the wastewater type (s = 0.6–86). Below that concentration, the flocculant underwent complexation, and no elimination could be observed. For most of the wastewaters, the required s values for at least 80% total P decrease were very similar for both FeIII and AlIII. Furthermore, Ca(OH)2 as flocculant turned out to be an effective tool for total P removal and simultaneous softening of calcareous concentrates.

Detlef Wischer

Papers

Fate of triphenyl phosphate in soil

Utilization of 2-phosphonobutane-1,2,4-tricarboxylic acid as source of phosphorus by environmental bacterial isolates.