Journal of Exposure Analysis and Environmental Epidemiology (2001) 11, 449 – 458 # 2001 Nature Publishing Group All rights reserved 1053-4245/01/$17.00
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Levels of persistent organic pollutants in several child day care centers
NANCY K. WILSON,a JANE C. CHUANGb AND CHRISTOPHER LYU a aBattelle, Durham, North Carolina bBattelle, Columbus, Ohio
The concentrations of a suite of persistent organic chemicals were measured in multiple media in 10 child day care centers located in central North Carolina. Five centers served mainly children from low-income families, as defined by the federal Women, Infants, and Children (WIC) assistance program, and five served mainly children from middle-income families. The targeted chemicals were chosen because of their probable carcinogenicity, acute or chronic toxicity, or hypothesized potential for endocrine system disruption. Targeted compounds included polycyclic aromatic hydrocarbons (PAHs), pentachloro- and nonyl-phenol, bisphenol-A, dibutyl and butylbenzyl phthalate, polychlorinated biphenyls (PCBs), organochlorine pesticides, the organophosphate pesticides diazinon and chlorpyrifos, and the herbicide 2,4-dichlorophenoxyacetic acid (2,4D). Sampled media were indoor and outdoor air, food and beverages, indoor dust, and outdoor play area soil. Concentrations of the targeted compounds were determined using a combination of extraction and analysis methods, depending on the media. Analysis was predominantly by gas chromatography/mass spectrometry (GC/MS) or gas chromatography with electron capture detection (GC/ECD). Concentrations of the targeted pollutants were low and well below the levels generally considered to be of concern as possible health hazards. Potential exposures to the target compounds were estimated from the concentrations in the various media, the children’s daily time–activity schedules at day care, and the best currently available estimates of the inhalation rates (8.3 m3 /day) and soil ingestion rates (100 mg/day) of children ages 3–5. The potential exposures for the target compounds differed depending on the compound class and the sampled media. Potential exposures through dietary ingestion were greater than those through inhalation, which were greater than those through nondietary ingestion, for the total of all PAHs, the phenols, the organophosphate pesticides, and the organochlorine pesticides. Potential exposures through dietary ingestion were greater than those through nondietary ingestion, which were greater than those through inhalation, for those PAHs that are probable human carcinogens (B2 PAH), the phthalate esters, and 2,4D. For the PCBs, exposures through inhalation were greater than those through nondietary ingestion, and exposures through dietary ingestion were smallest. Differences in targeted compound levels between the centers that serve mainly low-income clients and those that serve mainly middle-income clients were small and depended on the compound class and the medium. Journal of Exposure Analysis and Environmental Epidemiology (2001) 11, 449–458.
Keywords: air, child day care centers, children, diet, dust, multimedia, PAH, PCB, persistent organic pollutants, pesticides, soil.
Introduction pollutants because of the children’s immaturity, their rapid development, and their activities (Zahm and Devesa, In the early spring of 1997, we measured the concen- 1995; Heil et al., 1996; Mukerjee, 1998; Landrigan et al., trations of several organic pollutants occurring at low 1999). Their exposures may come from multiple media levels in 10 child day care centers (nine at which — including air, diet, dust and soil — and the routes of sampling was completed and one at which only partial these exposures may be inhalation (Ny et al., 1993; EFH, data were obtained) in the Durham–Chapel Hill–Raleigh, 2000), dietary and nondietary ingestion (Waldman et al., North Carolina area. The targeted compounds were 1991; Menzie et al., 1992; Stanek and Calabrese, 1995a,b; chosen because: they may persist in the indoor or the Lewis et al., 1999), and dermal absorption. Therefore, we outdoor environment; they are widely distributed (Wania measured the targeted compounds in indoor and outdoor and MacKay, 1996); they have been used in homes and air, food and beverages, indoor dust, and outdoor play schools; and they may result in acute or chronic toxicity area soil. The targeted compounds included polycyclic at high levels. Preschool children are considered espe- aromatic hydrocarbons (PAHs), pentachloro- and nonyl- cially susceptible to the deleterious effects of some phenol, bisphenol-A, polychlorinated biphenyls (PCBs), butylbenzyl and dibutyl phthalate, organochlorine pesti- cides such as DDT and chlordane, the organophosphate pesticides diazinon and chlorpyrifos, and the lawn 1. Address all correspondence to: Nancy K. Wilson, Battelle, 100 Capitola Drive, Suite 301, Durham, NC 27713-4411. Tel.: +1-919-544-3717 ext. herbicide 2,4-dichlorophenoxyacetic acid (2,4D). 140. Fax: +1-919-544-0830. In previous work, we found that the exposures of 24 Received 13 August 2001. preschool children to the B2 PAH, those that are considered Wilson et al. Persistent organic pollutants in child day care centers to be probable human carcinogens (IARC, 1997; IRIS, Sampling 1999), were derived largely from dietary and nondietary Indoor and outdoor air was sampled for a 48-h period at ingestion (Wilson et al., 1996; Chuang et al., 1999a). 4 l/min with a URG sampler (University Research Analysis of PAH exposures and potential doses in this day Glassware, Chapel Hill, North Carolina). The 10-m, care study and a subsequent nine-child study likewise impactor-equipped inlet was followed by a glass cartridge emphasized the importance of the ingestion routes of containing a quartz fiber filter followed by XAD-2 resin, exposure, especially for the PAH of low volatility (Wilson or containing a Teflon-coated glass filter followed by et al., 1999, 2000a). In the latter two studies, differences in polyurethane foam for 2,4D, to collect both particulate- the potential exposures to PAH were small and mostly and vapor-phase materials (Chuang et al., 1987, 1991, nonsignificant between day care center and home, and 1999b; Wilson et al., 1991, 1996). The indoor samplers between centers and children from low-income and were placed in a Styrofoam box equipped with a cooling middle-income families. fan, and then in a playpen with a net over the top to Our study objectives were to evaluate field methods for protect the equipment from curious children. The outdoor exposure measurement, to obtain concentration data on sampling pump and controls were housed in an persistent semivolatile and nonvolatile organic pollutants unoccupied shelter (a dog house, which we provided) (POPs), to estimate the range of concentrations of these located centrally in the children’s outdoor playground. POPs in the day care centers and identify the most common The air sampler inlets were placed at the approximate exposure media, and to examine possible differences among breathing height of the children, approximately 75 cm the day care centers serving low-income and middle- from the floor or ground. income clients. The information developed in this study was Classroom floor dust was collected with a High- also intended to aid us in the design of a later, larger field Volume Small Surface Sampler (HVS3; Cascade Stack study of preschool children’s exposures (ORD, 2000; Sampling Systems, Bend, Oregon) using a standard Wilson et al., 2000b). ASTM method (Lewis et al., 1994; ASTM, 1997) in the area where the children had the highest play activities. Playground soil was scraped from the top 0.5 cm of Methods exposed soil over a 0.1 m2 (1 ft2) area in the location identified by the teacher as being most used by the Selection of Day Care Centers children (Chuang et al., 1994, 1995). The surfaces of A national telephone database (Selectphone, ProCD) was these playground areas generally had no grass or, at most, used to identify child day care centers in the Raleigh– a few straggling blades. Durham–Chapel Hill area. Letters describing the study Duplicate plates (Acheson et al., 1980; Block, 1982; were sent to all 202 centers in the area, followed by WHO, 1985; Fennema and Anderson, 1991) of the daily telephone contacts. We then visited each center that meals served to the children in the participating class- expressed interest initially, talked to its director, room were collected on each of the two sampling days. explained the study, and offered a small monetary The same menus were served to all the children in a incentive (US$50) plus nonmonetary incentives, such given classroom. Two servings of each food were as small gifts for the classroom, for participation. collected. One serving was placed in a plastic container Twenty-nine centers (14%) agreed to participate. Of and one was placed in a glass container. The foods were the 29 centers, five are federally funded Head Start collected as composites for each day. Liquid and solid centers, about 90% of whose clients meet federal foods were collected separately and refrigerated until guidelines for low income (WIC, 1999), and the rest they were shipped under ice to the laboratory for are privately funded centers, most of whose clients are analysis. middle income. We selected five private and four Head Start centers, plus six back-up centers, for participation Analysis in the study. All of the selected centers have at least one The filter/XAD-2 air samples and field blanks were spiked classroom that serves preschool children ages 3–5. Three with surrogate recovery standards (SRS), and Soxhlet- centers are located in rural communities and six are located extracted with dichloromethane (DCM). The DCM extract in urban centers. At one of the urban centers, we were was concentrated by Kuderna–Danish evaporation, and unable to collect a full set of samples; therefore, we also divided into two portions. The first portion was analyzed by collected a complete set of samples at one of the back-up gas/chromatography/mass spectrometry (GC/MS) oper- centers, which is located in a similar urban neighborhood. ated in the electron impact (EI), selected ion monitoring Additional details on the recruitment and other methodo- (SIM) mode, for PAH, PCB, phthalates (PE), phenols (Ph), logical aspects of this study are reported elsewhere and organochlorine (OC) and organophosphate (OP) (Chuang et al., 1998). pesticides. Three GC/MS analyses were performed for
450 Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) Persistent organic pollutants in child day care centers Wilson et al. each extract: one for PAH and PE, one for PCB, and one for phthalate esters compared to the levels in samples that OC and OP. were collected in glass. For example, in food samples from Only the filter of the filter/PUF air samples was analyzed one day care center, the background levels of dibutyl for 2,4D, since our method evaluation tests (Chuang et al., phthalate were 220 ppb in glass and 290 ppb in plastic, and 1998) showed that the 2,4D is retained in the filter. The the background levels of benzylbutyl phthalate were 11 ppb filter was extracted sonically with a phosphate buffer in glass and 51 ppb in plastic. Therefore, only the results of solution, and the extract was processed through a C18 solid analyses of food samples collected in glass are reported phase extraction (SPE) column. The target fraction was here. concentrated, methylated, and analyzed by GC with electron All GC/MS analyses of sample extracts and standard capture detection (ECD) for 2,4D. solutions were done on a Hewlett-Packard GC/MS; Dust samples were separated into coarse and fine operated in SIM mode (70 eV EI), with a ChemStation ( <150 m) fractions. Information reported in the literature data system. The GC column was a DB-5 fused silica indicates that only the fine fraction contains significant capillary column (60 mÂ0.32 mm; 0.25 m film thick- quantities of the targeted organic pollutants (Lewis et al., ness), used with helium carrier gas. Following injection, the 1999). Also, the fine fraction is that most likely to adhere to GC column was held at 708C for 2 min, then programmed to and remain on human skin (Duggan et al., 1985; Que Hee 1508Cat158C/min, then to 2908Cat68C/min. Molecular et al., 1985; Driver et al., 1989). Therefore, only the fine ions and their associated characteristic fragment peaks were dust fraction was analyzed. Soil samples were not separated monitored. Identifications were based on the GC retention into fractions. Both dust and soil were spiked with a SRS times relative to those of corresponding internal standards and extracted twice each sonically with 10 ml of 10% and the relative abundances of the monitored ions. diethyl ether (EE) in hexane for 20 min. The extracts were Quantifications were based on comparisons of the inte- concentrated to 1 ml and applied to a Florisil SPE column, grated ion current responses of the target ions to those of the preconditioned with 50% EE in hexane followed by 100% corresponding internal standards using average response hexane. The fraction eluted with 12 ml of 15% EE in hexane factors of the target analytes generated from standard was concentrated and analyzed by GC/MS for PAH, PCB, calibrations. PE, OC, and OP. The detection limits of the target POP were estimated A second aliquot of each dust and soil sample was used from the analytes’ lowest signal-to-noise ratios at the for analysis of phenols. The samples were extracted lowest levels of standard calibrations. These limits of sequentially with 5% acetic acid in methanol, DCM, and detection (LODs) are given in Table 1. 5% acetic acid in distilled water. The mixture was washed Overall, 57 individual target compounds in six different with distilled water, and the DCM extract was concentrated. media — indoor air, outdoor air, floor dust, playground soil, One portion of the extract was methylated for pentachlor- solid food, and liquid food — were determined for each day ophenol (PCP), and the other portion was not methylated care center. Extensive details of the methods are provided and was analyzed for the other phenols. elsewhere (Chuang et al., 1998). A third dust/soil aliquot was extracted with phosphate buffer, cleaned up with C18 SPE, and analyzed for 2,4D by Estimates of Exposure Pathways GC/ECD (soil) or GC/MS (dust). The estimates of exposure to the targeted compounds The solid and liquid food samples that were collected in through inhalation are based on the time-weighted concen- glass containers from each of the centers were extracted tration, indoor and outdoor air levels, the amount of time separately and analyzed for target POP. Aliquots of the that children at the day care center spent outdoors and homogenized food samples were spiked with SRS, extracted indoors, and the portion of the 24-h day that the children with DCM, fractionated by gel permeation chromatography (GPC), and subjected to final clean-up with Florisil SPE. The target fractions were concentrated and analyzed by Table 1. Estimated LODs for the target analytes in multimedia samples. GC/MS for target PAH, PCB, PE, OC, and OP. 3 A second aliquot of the food sample was prepared for Compound class Air (ng/m ) Dust/soil (ppm) Food (ppb) 2,4D determination similarly to the soil/dust samples. Food 2,4-D 0.1 0.001 0.2–0.5 samples were spiked with SRS and extracted with phosphate OP pesticides 0.1 0.001 0.04 buffer. Partitioning with hexane and centrifuging were used OC pesticides 0.1 0.001 0.04 to remove fat. The aqueous layer was acidified and applied PCB 0.04 0.001 0.04 to a C18 SPE column. Target fractions were concentrated, B2 PAH 0.01–0.04 0.001 0.04 methylated, and analyzed by GC/MS for 2,4D. Total PAH 0.01–0.04 0.001 0.04 Similar analyses of food samples that were collected in Phenols 0.1 0.001 0.1 plastic containers showed high background levels of Phthalates 0.04 0.001 0.04
Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) 451 Wilson et al. Persistent organic pollutants in child day care centers spent at the day care center (EPA, 1994; ORETG, 1997). mental media at all the child care centers. Table 3 The times indoors and outdoors are based on the schedules summarizes the cumulative concentration data for the provided by each center. The total daily operation time of various compound classes in the sampled environmental the centers varied from 6 to 12 h. For the calculation, we media. In Table 3, the median concentration data for all assumed that a child spent the entire period at the center. centers are presented, as well as the means and ranges for Maximum exposure estimates through the inhalation route the two income groups of centers. These data are useful in are based on the following equation: planning larger-scale studies, such as the CTEPP study (ORD, 2000; Wilson et al., 2000b), which examine the E ¼ðC t þ C t ÞVF=1000ðt þ t Þ inh i i o o i o influence, if any, of family income on preschool children’s where E inh is the estimate of daily POP exposure through exposures to persistent pollutants. inhalation at the day care center (g/day), C i is the indoor Although vacuum bag samples were collected from 3 air POP concentration (ng/m ), C o is the outdoor air POP several of the centers, the concentration data from their 3 concentration (ng/m ), t i is the time the child spends analysis were not used in the exposure calculations, which indoors at the center (min), t o is the time the child spends indicate the children’s exposures over the 48-h sampling outdoors at the center (min), V is the child’s estimated period. The vacuum bag data represent, to some extent, the ventilation rate, which is assumed to be 8.3 m3 /day (EFH, concentrations of the targeted compounds over the area of 2000), and F is the fraction of the 24-h day that the child is the classroom or center and over time. However, losses of at the center. the more volatile compounds over time and lack of control Maximum exposure estimates through nondietary in- over the type of the vacuum cleaners limit their value in gestion were based on the dust and soil concentrations, the estimating exposure, except as a potential screening amounts of time indoors and outdoors, and the time that technique. child is at the center: As stated above, dermal exposures were assumed to be insignificant, compared to other routes of exposure, at the E ¼ðD t þ P t ÞMF=ðt þ t Þ n i i o o i o low levels found in this study. where E n is the estimate of daily POP exposure through The herbicide 2,4D was below the LOD in 4 of 10 indoor nondietary ingestion (g/day), D i is the concentration of air samples, 3 of 10 outdoor air samples, and 7 of 10 soil POP in dust (g/g), P o is the concentration in playground samples. soil (g/g), and M is the child’s daily dust/soil intake, The organophosphate pesticides diazinon and chlorpyr- which is assumed to be 100 mg/day (Stanek and ifos were at similar levels in both low- and middle- Calabrese, 1995a,b). income centers. Diazinon was found in all soil and dust The maximum exposure estimates through dietary samples, but was below the LOD in food except for two ingestion were based on the POP concentrations in solid samples in which it was found at 14.5 and 1.7 ppb. and liquid food samples, and the mass of the food samples: Chlorpyrifos was found in food at all centers. Its mean level was 0.5 ppb. E ¼ðS M þ L M Þ=2 d i s i l Use of many of the organochlorine pesticides has been where E d is the estimate of daily POP exposure through discontinued. Nevertheless, these compounds are widely dietary ingestion at the day care center (g/day), Si is the distributed and persistent. All the target OC pesticides POP concentration in the solid food samples (g/kg), L i is were found at low levels in classroom dust at all centers, the POP concentration in the liquid food samples (g/kg), as was gamma-chlordane in solid food. In soil, all the OC M s is the total weight of solid food served per child at the pesticides were at low levels or not detected. Several OC center during 48 h (kg), and M l is the total weight of liquid pesticides were below the LOD in most centers: aldrin, food served during 48 h (kg). dieldrin, and p,p0 -DDT in indoor air, outdoor air, soil, Dermal exposure is taken to be insignificant at the low liquid food, and solid food; endrin in outdoor air, soil, levels encountered in these samples, compared to the liquid food, and solid food; and lindane in liquid and solid contributions from other routes of exposure. food. PCBs were found at higher levels in indoor air compared to outdoor air, with a mean of 65 vs. 9.7 ng/m3, with low- Results and middle-income centers much the same. All liquid food samples and all, but one, solid food samples were below the Levels of Targeted Compounds LOD for PCB. Two centers had PCB levels in dust greater The results of the analyses for the various target than 24 ppm; soil at one center had PCB >1 ppm, with all compounds and compound classes are summarized in others at approximately 0.1 ppm. Tables 2 and 3. Table 2 presents concentration data for the Targeted PAHs were found in all samples, with individual target compounds in several sampled environ- indoor air, dust, soil, and liquid food levels higher at
452 Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) Persistent organic pollutants in child day care centers Wilson et al.
Table 2. Concentrations of the target compounds in multiple media at several child day care centers.
Compound Indoor air (ng/m3) Outdoor air (ng/m3) Floor dust HVS3 sample (ppm) Solid food (ppb) Mean Range Mean Range Mean Range Mean Range 2,4-D 0.17 <0.1–0.47 0.253 <0.1–0.544 0.181 0.02–0.618 1.35 0.26–3.14
OP pesticides Diazinon 15.9 3.75–62.4 1.99 <0.1–4.33 0.223 0.041–0.799 1.64 0.04–14.5 Chlorpyrifos 9.35 1.26–21.7 7.92 0.755–25.7 0.578 0.032–1.231 0.772 0.37–1.6
OC pesticides Lindane 6.19 1.17–13.1 4.58 2.03–7.22 0.013 0.004–0.034 <0.04 <0.04 Heptachlor 53.8 6.10–336 4.04 1.61–6.40 0.253 0.02–1.234 1.51 <0.04–4.51 Aldrin 0.067 <0.1–0.223 0.143 <0.1–0.984 0.014 0.002–0.037 <0.04 <0.04 Gamma chlordane 6.23 0.303–29.1 0.342 0.174–0.892 0.234 0.036–0.689 0.172 0.12–0.25 Alpha chlordane 3.86 0.262–19.3 0.268 0.166–0.503 0.148 0.01–0.565 0.092 <0.04–0.18 p,p0-DDE 0.359 0.192–0.591 0.177 <0.1–0.459 0.101 0.03–0.254 0.225 <0.04–0.88 Dieldrin 0.364 <0.1–1.56 <0.1 <0.1 0.500 0.014–1.47 <0.08 <0.08 Endrin 1.60 <0.1–3.26 0.729 <0.04–2.19 0.071 0.011–0.228 <0.04 <0.04 p,p0-DDT 0.175 <0.1–0.882 <0.1 <0.1 0.073 0.016–0.211 0.101 <0.04–0.83
Chlorinated biphenyls 2-Cl 3.82 0.66–16.6 1.49 0.289–3.496 0.001 <0.002–0.003 0.026 <0.04–0.08 4-Cl 0.366 <0.04–1.19 0.311 <0.04–0.765 <0.002 <0.002 <0.04 <0.04
2,6-Cl2 7.81 1.06–19.3 1.53 <0.04–5.88 0.007 <0.002–0.042 <0.04 <0.04 0 4,4 -Cl2 2.38 <0.04–21.4 0.132 <0.04–0.337 0.015 <0.002–0.134 <0.04 <0.04 0 2,4,4 -Cl3 15.6 <0.04–130 1.53 0.654–2.84 0.136 <0.002–1.194 <0.04 <0.04 0 0 2,2 ,3,5 -Cl4 3.56 0.136–17.3 0.766 0.317–2.30 0.126 <0.002–0.456 <0.04 <0.04 0 0 2,2 ,5,5 -Cl4 6.45 0.692–25.9 1.67 1.24–2.36 0.18 0.008–0.737 <0.04 <0.04 0 0 2,3 ,4 ,5-Cl4 2.65 0.056–16.7 0.303 0.184–0.415 0.087 <0.002–0.353 <0.04 <0.04 0 0 3,3 ,4,4 -Cl4 0.048 <0.04–0.077 0.093 0.045–0.168 0.01 <0.002–0.027 <0.04 <0.04 0 0 2,2 ,3,5 ,6-Cl5 4.44 0.066–38.2 0.384 0.142–0.676 0.497 <0.002–2.842 <0.04 <0.04 0 0 2,2 ,4,5,5 -Cl5 5.21 0.05–47.0 0.236 0.052–0.521 0.852 <0.002–4.903 <0.04 <0.04 0 0 2,2 ,3,4,5 -Cl5 2.33 <0.04–20.6 0.05 <0.04–0.175 0.452 <0.002–2.587 <0.04 <0.04 0 0 2,3,3 ,4 ,6-Cl5 4.90 0.143–43.1 0.38 0.233–0.598 1.02 <0.002–5.86 <0.04 <0.04 0 0 2,3 ,4,4 ,5-Cl5 2.13 <0.04–19.4 0.131 <0.04–0.251 0.524 <0.002–3.00 <0.04 <0.04 0 0 2,3,3 ,4,4 -Cl5 0.579 <0.04–4.91 0.053 <0.04–0.151 0.157 <0.002–0.868 <0.04 <0.04 0 0 3,3 ,4,4 ,5-Cl5 0.025 <0.04–0.047 0.029 <0.04–0.091 0.066 <0.002–0.256 <0.04 <0.04 0 0 0 2,2 ,4,4 ,5,5 -Cl6 1.25 <0.04–10.5 0.087 <0.04–0.153 0.194 <0.002–1.06 <0.04 <0.04 0 0 0 2,2 ,3,4,4 ,5 -Cl6 <0.88 <0.04–8.32 0.041 <0.04–0.131 0.454 <0.002–2.60 <0.04 <0.04 0 0 0 3,3 ,4,4 ,5,5 -Cl6 <0.04 <0.04 0.036 <0.04–0.104 0.067 0.011–0.174 <0.04 <0.04 0 0 0 2,2 ,3,4,4 ,5,5 -Cl7 0.074 <0.04–0.489 <0.04 <0.04 0.434 <0.002–2.50 <0.04 <0.04
PAH a BaA 0.109 0.073–0.145 0.045 0.022–0.087 0.195 0.031–0.562 0.172 0.02–0.54 Chrysene 0.108 0.060–0.147 0.063 <0.01–0.138 0.374 0.036–1.21 0.296 0.02–0.97 BbF 0.128 <0.04–0.165 0.105 0.05–0.228 0.416 0.025–1.29 <0.04 <0.04 BkF 0.081 <0.04–0.107 0.038 0.019–0.08 0.137 0.007–0.433 0.027 <0.04–0.09 BaP 0.103 0.054–0.156 0.028 0.013–0.057 0.292 0.015–0.82 <0.04 <0.04 In123cdP 0.064 <0.04–0.09 0.058 0.022–0.133 0.206 0.002–0.786 <0.04 <0.04 DahA <0.04 <0.04 0.014 <0.01–0.021 0.054 0.003–0.207 <0.04 <0.04 Naphthalene 205 92.2–584 85.4 22.0–263 0.008 0.001–0.026 0.939 0.3–3.99 Biphenyl 23.9 10.2–52.8 9.03 3.22–16.9 0.004 0.001–0.008 0.213 0.08–0.41 (continued on next page)
Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) 453 Wilson et al. Persistent organic pollutants in child day care centers
Table 2. (continued).
Compound Indoor air (ng/m3) Outdoor air (ng/m3) Floor dust HVS3 sample (ppm) Solid food (ppb) Mean Range Mean Range Mean Range Mean Range Acenaphthylene 2.24 1.25–3.72 1.60 0.475–4.06 0.006 0.001–0.018 0.252 <0.04–1.1 Acenaphthene 6.68 2.14–28.7 3.43 1.24–8.85 0.013 <0.001–0.05 0.634 <0.04–1.98 Fluorene 4.05 2.70–6.07 3.83 2.27–7.77 0.01 0.004–0.019 0.433 0.11–1.19 Phenanthrene 21.0 3.65–135 7.14 3.46–16.0 0.263 0.049–0.875 0.823 0.51–1.15 Anthracene 0.827 0.471–2.69 0.256 0.106–0.433 0.024 0.007–0.076 0.036 <0.04–0.11 Fluoranthene 0.621 0.361–1.00 0.83 0.416–1.46 0.502 0.077–1.83 0.299 0.17–0.54 Pyrene 0.373 0.236–0.529 0.628 0.302–1.53 0.402 0.066–1.46 0.205 <0.04–0.43 CcdP <0.04 <0.04 0.023 <0.01–0.188 0.057 0.011–0.146 <0.04 <0.04 BeP 0.105 0.035–0.15 0.058 0.022–0.122 0.225 0.015–0.662 0.033 <0.04–0.15 BghiPer 0.066 <0.04–0.104 0.073 0.028–0.184 0.198 <0.001–0.725 0.055 <0.04–0.37 Coronene <0.04 <0.04 0.039 <0.01–0.109 0.053 0.001–0.206 <0.04 <0.04
Phenols Pentachloro- 2.711 0.463–17.6 0.376 0.247–0.499 0.124 0.041–0.271 NAb NA Nonyl-c 203 52.0–527 72.3 31.3–111 8.44 4.16–13.8 43.4 22.3–63.0 Bisphenol-A 0.734 <0.1–1.80 0.884 <0.1–2.50 2.26 1.04–4.51 4.24 <0.1–7.9
Phthalates Dibutyl 239 108–404 112 51.6–191 18.4 1.58–46.3 218 144–363 Benzylbutyl 100 11.6–581 130 15.8–733 67.7 15.1–175 24.4 4.11–102 aPolycyclic aromatic hydrocarbons: BaA= benz[a]anthracene; BbF = benzo[b]fluoranthene; BkF = benzo[k]fluoranthene; BaP = benzo[a]pyrene; In123cdP = indeno[1,2,3-cd]pyrene; DahA= dibenz[ah]anthracene; CcdP = cyclopenta[cd]pyrene; BeP = benzo[e]pyrene; BghiPer = benzo[ghi]perylene. bNot available. cSum of nonyl phenols. low-income centers. The B2 PAHs, which are classified These B2 PAHs were at higher levels in soil at the as probable human carcinogens (IARC, 1997; IRIS, low-income centers compared to the middle-income 1999), were below the LOD in all liquid food samples. centers.
Table 3. Concentrations of targeted groups of persistent organic pollutants in multiple media at several child day care centers.
Compounds Medium Median, Low-income rangeb Low-income Middle-income Middle-income all centersa meana rangeb meana 2,4-Dc Indoor air, ng/m3 0.164 <0.1–0.225 (3/4) 0.094 <0.1– 0.474 (1/6) 0.221 Outdoor air, ng/m3 0.206 <0.1–0.322 (2/4) 0.160 <0.1–0.544 (1/6) 0.315 Dust, ppm (HVS3)d 0.139 0.020–0.235 0.106 0.024–0.618 0.224 Soil, ppm <0.001 <0.001–0.007 (2/4) 0.003 <0.001–0.005 (5/6) 0.001 Solid food, ppb 1.38 0.28–3.14 1.29 0.26–2.47 1.40 Liquid food, ppb 0.61 0.20–0.64 0.338 0.39–2.36 1.45 OP pesticides Indoor air, ng/m3 15.2 13.7–47.7 29.0 8.23–76.1 22.7 Outdoor air, ng/m3 6.35 3.18–30.0 12.2 0.76–26.2 8.38 Dust, ppm (HVS3) 0.799 0.623–1.35 0.937 0.096–1.55 0.723 Dust, ppm (vacuum bag)d 1.34 0.742–2.18 1.42 0.535–5.08 2.06 Soil, ppm 0.007 0.006–0.088 0.029 0.004–0.040 0.012 Soil food, ppb 0.645 0.55–15.2 4.24 0.37–2.7 1.16 Liquid food, ppb 0.06 <0.04–0.26 (2/4) 0.133 <0.04–0.180 (3/6) 0.073 OC pesticides Indoor air, ng/m3 39.1 18.7–81.9 48.3 16.5–358 88.7 Outdoor air, ng/m3 11.0 7.00–15.5 11.1 4.26–13.2 9.55 (continued on next page)
454 Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) Persistent organic pollutants in child day care centers Wilson et al.
Table 3. (continued)
Compounds Medium Median, Low-income range b Low-income Middle-income Middle-income all centers a mean a range b mean a Dust, ppm (HVS3) 1.23 0.597–1.66 1.17 0.761–3.62 1.54 Dust, ppm (vacuum bag) 2.06 1.32–2.16 1.84 1.22–4.04 2.45 Soil, ppm 0.018 0.005–0.034 0.013 0.007–0.070 0.029 Solid food, ppb 1.70 0.25–2.26 0.813 0.48–5.46 2.88 Liquid food, ppb 1.03 <0.04–2.00 (1/4) 1.15 <0.04–1.20 (1/6) 0.447 PCB Indoor air, ng/m 3 15.0 5.71–246 70.4 8.72–258 60.4 Outdoor air, ng/m 3 8.20 7.71–15.5 10.9 6.44–9.42 7.96 Dust, ppm (HVS3) 0.354 0.143–2.76 1.05 0.072–28.2 7.69 Dust, ppm (vacuum bag) 0.525 0.139–1.99 0.785 0.120–3.15 2.45 Soil, ppm 0.006 e 0.001–0.016 0.007 0.001–0.009 0.006 Solid food, ppb <0.04 <0.04 (4/4) <0.04 <0.04 (6/6) <0.04 Liquid food, ppb <0.04 <0.04 (4/4) <0.04 <0.04 (6/6) <0.04 B2 PAH Indoor air, ng/m 3 0.616 0.557–0.771 0.638 0.246–0.703 0.553 Outdoor air, ng/m 3 0.317 0.248–0.705 0.423 0.153–0.517 0.300 Dust, ppm (HVS3) 0.583 0.303–4.50 1.76 0.130–5.29 1.62 Dust, ppm (vacuum bag) 1.73 0.709–3.67 2.04 0.902–100 26.3 Soil, ppm 0.270 0.052–5.59 1.56 0.012–0.075 0.038 Solid food, ppb 0.475 0.050–0.680 0.323 0.080–1.01 0.580 Liquid food, ppb <0.04 <0.04 (4/4) <0.04 <0.04 – 0.410 (4/6) 0.090 Total PAH Indoor air, ng/m 3 192 171–690 405 116–241 172 Outdoor air, ng/m 3 88.5 75.8–317 152 35.1–139 86.4 Dust, ppm (HVS3) 1.22 0.600–9.98 4.12 0.388–9.42 3.05 Dust, ppm (vacuum bag) 4.49 1.61–8.18 4.76 2.07–218 57.2 Soil, ppm 0.182 0.167–13.1 3.72 0.060–0.255 0.134 Solid food, ppb 3.66 1.87–4.32 2.86 3.15–9.15 5.30 Liquid food, ppb 0.745 0.600–3.12 1.84 0.530–3.31 1.07 Phenols Indoor air, ng/m 3 216 153–529 298 52.8–223 146 Outdoor air, ng/m 3 81.3 76.3–113 93.3 31.6–107 60.3 Dust, ppm (HVS3) 9.77 5.35–15.3 11.1 5.51–16.5 10.7 Dust, ppm (vacuum bag) 32.4 12.5–153 64.5 19.7–60.2 38.6 Soil, ppm 0.255 0.187–0.97 0.471 0.136–0.305 0.244 Solid food, ppb 49.8 28.6–68.6 44.5 36.6–57.9 49.8 Liquid food, ppb 7.64 <0.1–10.1 (1/4) 5.40 6.43–10.3 7.92 Phthalates Indoor air, ng/m 3 251 230–985 513 121–448 224 Outdoor air, ng/m 3 193 129–876 417 73.3–200 125 Dust, ppm (HVS3) 61.2 38.4–61.2 54.7 22.9–221 104 Dust, ppm (vacuum bag) 113 81–140 11.1 93.6–556 260 Soil, ppm 0.264 0.247–1.22 0.502 0.231–1.24 0.425 Solid food, ppb 216 188–279 214 154–387 261 Liquid food, ppb 33.2 22.5–86.5 51.4 16.6–86.4 39.7 aMean and median values are calculated using one half the detection limit for those samples for which the targeted compounds were at concentrations below the LOD of the method. Data are shown for four low-income and six middle-income centers (see text). bThe number of samples below the detection limit is shown in parentheses, for example, (3/4) indicates three of the four samples were at concentrations below the LOD of the method. c2,4-D=2,4-dichlorophenoxyacetic acid; OP pesticides=sum of diazinon and chlorpyrifos; OC pesticides=sum of all targeted organochlorine pesticides; PCB=sum of all targeted polychlorinated biphenyls; B2 PAH=sum of all targeted PAHs that are designated as probable human carcinogens; Total PAH=sum of all targeted PAHs; Phenols=sum of pentachlorophenol, nonyl phenols, and bisphenol-A; Phthalates=sum of butylbenzyl and dibutyl phthalates. dHVS3=dust sample collected during the 48-h sampling period with the HVS3 surface sampler; Vacuum bag=vacuum bag sample from cleaning over the previous month using the center’s regular vacuum cleaner. For the HVS3, n=4 for low-income and n=7 for middle-income centers. For the vacuum bags, n=3 for the low-income and n=4 for the middle-income centers.
Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) 455 Wilson et al. Persistent organic pollutants in child day care centers
The targeted phenols were found in all samples, except food, two indoor air, and three outdoor air samples. that bisphenol-A was below the LOD in all, but one, liquid Pentachlorophenol levels were higher in the middle-income
Figure 1. The mean daily child’s potential intake of several persistent organic pollutants through multiple pathways while at day care (g/day). The lower chart is an expanded version of the upper chart, with data for the phenols and phthalates omitted.
456 Journal of Exposure Analysis and Environmental Epidemiology (2001) 11(6) Persistent organic pollutants in child day care centers Wilson et al. centers, possibly due to exposure to treated wood, as has Differences in pollutant concentrations were small and been suggested by higher chlorinated dioxin blood levels in probably not significant, given the small number of centers day care employees previously exposed to treated wood in this study, between the centers that serve low-income (Vonmanikowsky et al., 1998). families and those that serve middle-income families. Phthalate esters above the LODs were found in all Indoor air levels of all compounds in all centers were higher samples. After correction for the high levels of the targeted than those in outdoor air. phthalates found in the field and laboratory blanks, there were still concentrations of phthalates several orders of magnitude above the LOD in all samples. Acknowledgments
We thank Ying-Liang Chou, Patrick J. Callahan, Marcia Discussion Nishioka, Kimberlea Andrews, Mary A. Pollard, Laura Brackney, Charles Hines, Dave B. Davis, Ronald Menton, The results of these calculations of the exposures and Sydney Gordon for their contributions to this study. (maximum daily intakes) that a child may get while at Although the research described in this article has been the day care center are shown in Figure 1. It can be seen funded in part by the United States Environmental Protection that the highest exposures are to the phthalates and the Agency through Contract 68-D4-0023 to Battelle, it has not phenols, both of which are associated primarily with been subjected to Agency review. Therefore, it does not dietary ingestion. The large contribution to exposure of necessarily reflect the views of the Agency. Mention of trade the dietary ingestion route is evident for most compounds. names or commercial products does not constitute an However, inhalation also contributes to exposure, espe- endorsement or recommendation for use. cially for PCBs, but also for the phenols and the OC and OP pesticides. This is consistent with the findings of NOPES (Nonoccupational Pesticide Exposure Study; References Whitmore et al., 1994) that inhalation, as well as dietary ingestion, contributes to exposures for the cyclodiene Acheson K.J., Campbell I.T., Edholm O.G., Miller D.S., and Stock M.J. The measurement of food and energy intake in man — an evaluation termiticides and several home pesticides. Furthermore, of some techniques. Am J Clin Nutr 1980: 33: 1147–1154. nondietary ingestion, presumably from dust and children’s ASTM. Standard practice for collection of floor dust for chemical analysis hand-to-mouth activities, may play a role in the potential D5438-94. Annual Book of ASTM Standards, American Society for for exposure of these young children to the phthalates, B2 Testing and Materials, Vol. 11.03. West Conshohoken, Pennsylvania, PAH, PCB, and 2,4D. Support for the role of nondietary 1997, pp. 517–523. Block G. A review of validations of dietary exposure assessment methods. ingestion in the exposure of young children to persistent Am J Epidemiol 1982: 115: 492–505. pollutants comes from the finding that pesticides can Byrne S.L., Shurdut B.A., and Saunders D.G. Potential chlorpyrifos accumulate on toys and other sorbent materials in the exposure to residents following standard crack and crevice treatment. home and persist for at least 2 weeks after application of Environ Health Perspect 1998: 106 (11): 725–731. chlorpyrifos (Gurunathan et al., 1998), although others Chuang J.C., Hannan S.W., and Wilson N.K. Field comparison of polyurethane foam and XAD2 resin for air sampling for poly- have suggested that carpet dust does not contribute nuclear aromatic hydrocarbons. Environ Sci Technol 1987: 21 (8): significantly to exposure to this pesticide by nondietary 798–804. ingestion (Byrne et al., 1998). Chuang J.C., Mack G.A., Kuhlman M.R., and Wilson N.K. Polycyclic In this study of the levels of persistent organic pollutants aromatic hydrocarbons and their derivatives in indoor and outdoor air in multiple media at several child day care centers, the in an eight-home pilot study. Atmos Environ 1991: 25B: 369–380. Chuang J.C., Gordon S.M., Roberts J.W., Han W., and Ruby M.G. routes of potential exposure differed depending upon Evaluation of HVS3 sampler for sampling polycyclic aromatic compound class and medium. Based on the data presented hydrocarbons and polychlorinated biphenyls. EPA/600/R-94/188, herein, the exposure pathways for the target compounds 1994. rank from greater to lesser contributions as follows: Chuang J.C., Callahan P.J., Menton R.G., Gordon S.M., Lewis R.G., and Wilson N.K. Monitoring methods for polycyclic aromatic hydro- o carbons and their distribution in house dust and track-in soil. Environ Dietary ingestion>inhalation>nondietary ingestion for Sci Technol 1995: 29: 494–500. the total PAH, phenols, organophosphate pesticides, and Chuang J.C., Lyu C., Chou Y-L., Callahan P.J., Nishioka M., Andrews K., organochlorine pesticides; Pollard M.A., Brackney L., Hines C., Davis D.B., and Menton R. o Dietary ingestion>nondietary ingestion>inhalation for Evaluation and application of methods for estimating children’s the PAHs that are probable carcinogens (B2 PAH), exposure to persistent organic pollutants in multiple media. EPA 600/R-98/164a, 164b, and 164c, 1998. phthalate esters, and 2,4D herbicide; and Chuang J.C., Callahan P.J., Lyu C.W., and Wilson N.K. Polycyclic o Inhalation>nondietary ingestion> >dietary ingestion for aromatic hydrocarbon exposures of children in low-income families. the PCBs. J Expos Anal Environ Epidemiol 1999: 9: 85–98.
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