Article pubs.acs.org/est
Spatial and Temporal Trends of Particle Phase Organophosphate Ester Concentrations in the Atmosphere of the Great Lakes Amina Salamova,† Angela A. Peverly,‡ Marta Venier,† and Ronald A. Hites*,† †
School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States Science and Mathematics Department, Eureka College, Eureka, Illinois 61530, United States
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S Supporting Information *
ABSTRACT: The concentrations of six organophosphate esters (OPEs) in atmospheric particle phase samples collected once every 12 days at five sites in the North American Great Lakes basin over the period of March 2012 to December 2014, inclusive, are reported. These OPEs include tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), and tris(1,3-dichloroisopropyl) phosphate (TDCIPP), tri-n-butyl phosphate (TNBP), triphenyl phosphate (TPHP), and 2-ethylhexyl diphenyl phosphate (EHDP). Median total OPE concentrations (∑OPE) ranged from 93 pg/m3 at Sleeping Bear Dunes to 1046 pg/m3 at Chicago. The ∑OPE levels were significantly (P < 0.05) higher at Chicago and Cleveland, our urban sites, than at our rural and remote sites. The composition profiles were dominated by chlorinated OPEs at the urban and rural sites and by nonchlorinated OPEs at the remote sites. The concentrations of all OPEs were significantly (P < 0.001) correlated to one another, suggesting that these compounds share similar sources. Most atmospheric ∑OPE concentrations were significantly (P < 0.05) decreasing over time, with halving times of about 3.5 years at the urban sites and about 1.5 years at the rural and remote sites. Interestingly, TCEP and EHDP concentrations were increasing over time at the rural and remote sites with doubling times of 2.2 and 3.7 years, respectively.
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phosphate (TCIPP),20 also an additive flame retardant. TCIPP is used extensively in flexible and rigid foam for construction applications. During the period 1990−2002, the United States produced or imported about 5000−25 000 metric tonnes per year of TCIPP.21 Tris(1,3-dichloroisopropyl) phosphate (TDCIPP) has been used in plastics, foam, textiles, varnishes, electronic equipment, and furniture.2 Annual United States production of TDCIPP was estimated to be about 4500 and 23 000 tonnes in 1998 and 2006, respectively.2 2Ethylhexyl diphenyl phosphate (EHDP) is primarily a PVC plasticizer used in food packaging, and its annual United States production and import volume has been 500−5000 metric tonnes per year since 1986.22 Triphenyl phosphate (TPHP) is used in PVC and PVC/ABS plastics, polyurethane foams, hydraulic fluids, and nail polish. It is also a component of Firemaster 550, a flame retardant that is being used as a replacement for the phased-out Penta- and Octa-BDE commercial mixtures, and other flame retardant formulations that are added to polyurethane foam. The United States’ production and import volumes of TPHP were 5000−25 000 metric tonnes per year for the years of 1998, 2002, and 2006.22 TNBP, like many nonhalogenated OPEs, is used as a plasticizer
INTRODUCTION Organophosphate esters (OPE) are industrial chemicals that are widely used as flame retardants, plasticizers, antifoaming agents, and as additives in hydraulic liquids, lacquers, and floor polishes. These chemicals have been in heavy use for decades, and due to worldwide restrictions on brominated flame retardants, OPE production and use are expected to increase in the future.1,2 Because most OPEs are not physically bound to the material in which they are used, they can escape from these materials and enter the environment. Although the first reports of OPEs in the environment date back to the 1970s,3,4 scientific interest in OPEs has recently re-emerged. OPEs have been found in surface5,6 and groundwater,7 sediment;8 indoor, ambient,9 and personal air;10 indoor dust;11,12 fish;13 biota;14 and humans.15−18 Studies on the bioaccumulation and toxicity of OPEs are still limited, but some OPEs have been reported to be mutagenic, carcinogenic, and neurotoxic; they may also be developmental and reproductive toxins.2 Generally, halogenated OPEs are mostly used as flame retardants, and nonhalogenated OPEs are mostly used as plasticizers and in other applications. Tris(2-chloroethyl) phosphate (TCEP) was historically used as a flame retardant in polyurethane foam, but its use declined significantly from ∼10 000 tonnes in 1989 to
