Towards a regional passive air sampling network and ...

Science of the Total Environment 573 (2016) 1294–1302

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Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv

Towards a regional passive air sampling network and strategy for new POPs in the GRULAC region: Perspectives from the GAPS Network and first results for organophosphorus flame retardants Cassandra Rauert a, Tom Harner a,⁎, Jasmin K. Schuster a, Karen Quinto a, Gilberto Fillmann b, Luisa Eugenia Castillo c, Oscar Fentanes d, Martín Villa Ibarra e, Karina S.B. Miglioranza f, Isabel Moreno Rivadeneira g, Karla Pozo h, Andrea Padilla Puerta i, Beatriz Helena Aristizábal Zuluaga j a

Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, ON, M3H 5T4, Canada Universidade Federal do Rio Grande, Instituto de Oceanografia, Rio Grande, RS, Brazil c Central American Institute for Studies on Toxic Substances, Heredia, Costa Rica d CENICA/INE, Naucalpan de Juárez, Mexico e Instituto Tecnológico Superior de Cájeme, Cájeme, Sonora, México f Universidad Nacional de Mar del Plata, CONICET, Mar del Plata, Argentina g Laboratorio de Física de La Atmósfera, Instituto de Investigaciones Física, UMSA, La Paz, Bolivia h Universidad Católica de la Santísima Concepción, Facultad de Ciencias, Concepción, Chile i Universidad Nacional de Colombia, Arauca, Colombia j Universidad Nacional de Colombia, Manizales, Colombia b

H I G H L I G H T S

G R A P H I C A L

A B S T R A C T

• Special initiative has been implemented addressing monitoring limitations in GRULAC. • First reported data of organophosphorus flame retardants in the GRULAC region • TCPP dominated at most sites with TBEP dominating the profiles in Chile. • Key issues, limitations and challenges with program implementations are discussed.

a r t i c l e

i n f o

Article history: Received 19 May 2016 Received in revised form 28 June 2016 Accepted 28 June 2016 Available online 18 July 2016 Editor: D. Barcelo

⁎ Corresponding author. E-mail address: [email protected] (T. Harner).

http://dx.doi.org/10.1016/j.scitotenv.2016.06.229 0048-9697/© 2016 Elsevier B.V. All rights reserved.

a b s t r a c t A discussion is presented on the limitations for air monitoring studies around the Group of Latin American and Caribbean Countries (GRULAC), highlighting key issues requiring further attention, and reports on how a special initiative is addressing these limitations. Preliminary results are presented for the first reported data on organophosphorus flame retardant (OPFR) concentrations in outdoor air from the GRULAC region. At the majority of sites the concentrations and the profile of the OPFRs detected were similar with tris (chloroisopropyl) phosphate (TCPP) dominating (b MDL to 1280 pg/m3). However, the urban location at Concepción, Chile presented higher

C. Rauert et al. / Science of the Total Environment 573 (2016) 1294–1302

Keywords: GRULAC region GAPS Network OPFRs Regional monitoring programs

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concentrations and a different profile with tris (2-butoxyethyl) phosphate (TBEP) dominating (mean 800 pg/m3 vs 80 pg/m3 at the other locations) –indicating different sources at this location. OPFRs, used extensively as flame retardants and plasticizers, are found ubiquitously in indoor environments yet only few studies report outdoor air levels. This preliminary study of only 7 sites highlights how extensive regional passive sampling networks (such as GAPS) can provide important new information to support risk assessment of these and similar chemicals. Finally, the various challenges with implementing a regional monitoring program are discussed, including harmonizing data from various monitoring programs for reporting to the GMP. © 2016 Elsevier B.V. All rights reserved.

1. Introduction The Global Atmospheric Passive Sampling Network (GAPS, http:// www.ec.gc.ca/rs-mn/default.asp?lang=En&n=22D58893-1) was established in 2004/2005 to support the needs of the Global Monitoring Plan (GMP) of the Stockholm Convention on persistent organic pollutants (POPs) (Harner et al., 2006; UNEP, 2007). GAPS provides unique global scale information for assessing regional and long-range transport of POPs and emerging chemicals in air (Pozo et al., 2006; Pozo et al., 2008) and for evaluating global emissions estimates and the performance of global transport models (Genualdi et al., 2011; Schuster et al., 2015). Measurements from GAPS have contributed to the regional reports of the GMP and in some cases represent the only data for some regions (UNEP, 2016a). The data provided by GAPS are considered to be ‘comparable’ because they originate from the same laboratory and are therefore subject to the same biases and analytical artefacts (Su et al., 2011). This comparability of the data adds to their value for understanding regional and global-scale trends and transport of POPs in air. The GAPS program is coordinated through a central laboratory operated by Environment and Climate Change Canada (ECCC), where samples are initially prepared and then returned for analysis following sample collection. In addition to its international activities, GAPS also contributes to Canadian domestic risk assessment and risk management needs under the Chemicals Management Plan (Government of Canada, 2016). The ECCC principal investigators for GAPS collaborate with GAPS partners (individuals and/or institutions) to carry out sample deployment for the GAPS program and also to assist in training, and implementation of special passive sampling studies at the local or regional scale using polyurethane foam (PUF) disk type passive samplers that provide a time-integrated measure of concentrations in air over seasonal resolution e.g. 2–3 month periods. In most cases, seasonally resolved data is sufficient for assessing spatial and temporal trends for POPs and for model/emissions evaluation purposes. A big advantage of passive samplers compared to conventional high volume air samplers is that they can be deployed anywhere, do not require electricity, and are inexpensive to maintain. A disadvantage of PUF sampling is that concentrations represent an average of air concentrations over the sampling period, therefore variations (e.g. diurnal) cannot be determined. However for a background air assessment such as this type of study they are ideal. A strong partnership exists between the GAPS Network and researchers in the Group of Latin American and Caribbean Countries (GRULAC) region. For instance, one of the first regional studies using the PUF disk samplers took place in Chile in 2002/03 (Pozo et al., 2004) and demonstrated the feasibility and practicality of using PUF disk samplers to map concentrations of POPs at the continental scale and to couple passive sampling with air parcel back trajectory density plots to evaluate source-receptor relationships. GAPS special studies in the GRULAC region have also contributed to the understanding of POPs transport in mountainous regions in Bolivia (Estellano et al., 2008) and Brazil (Meire et al., 2012a; Meire et al., 2012b). The use of PUF disk samplers has expanded throughout the GRULAC region to address regional and local needs for air quality and health assessment in urban (Cortés et al., 2014; Cortés et al., 2016; Gouin et al., 2008; Pozo et al., 2015), agricultural (Tombesi et al., 2014) and background regions (Estellano et al., 2008; Pozo et al., 2012). In addition to GAPS, there have

been other regional-scale monitoring initiatives in the GRULAC region that have employed passive air samplers. These include: i.) the Latin American Passive Atmospheric Sampling Network (LAPAN) network (UNEP, 2016a), operating since 2010 at N70 sites across the region and employs XAD-tube samplers (deployed for 1 year periods) and ii.) a regional capacity building project funded by the Global Environmental Facility (GEF) that employs PUF disk samplers (UNEP, 2016b; Bogdal et al., 2012; Leslie et al., 2013). Despite the advances in POPs air monitoring and research in the GRULAC region over the past decade, some limitations continue to exist. Two key issues that require further attention include: i.) Lack of information on “new” POPs in air. Although GRULAC studies (GAPS and independent studies) are now addressing the older listed POPs in air, there is a general lack of information on the newly listed POPs, emerging contaminants, and candidate POPs being considered for listing by the POPs Review Committee (POPRC) of the Stockholm Convention (UNEP, 2016c). The lack of measurement and monitoring data results in limited information contributing to international and domestic risk assessment of these chemicals and also the ability to evaluate their long-range transport or to develop and evaluate global transport models and emissions estimates. ii.) Need for a sustainable, long-term regional air monitoring strategy for the GMP. Although the collaboration between the GAPS program and GRULAC region partners has contributed valuable new information on POPs and supported regional reporting requirements under the GMP, a long term regional strategy to support the GMP has not yet been developed.

The current lack of information on POPs in the GRULAC region is being addressed through a special initiative under the GAPS Network that started in 2012. This has led to the expansion of GAPS sites in the region to a total of 19 sites and has resulted in the first regional-scale monitoring data for polychlorinated dioxins and furans (PCDD/Fs) (Schuster et al., 2015). Starting in 2014, this expanded GAPS-GRULAC network has shifted its attention to other compound classes including emerging contaminants, candidate POPs and new POPs. In this study, the first results are presented for the organophosphorus flame retardants (OPFRs). OPFR production and application has increased since the phase out of several high-production brominated flame retardants in the early 2000s (van der Veen and de Boer, 2012). They are commonly used as flame retardants or plasticisers and are being reported in environmental media in an increasing number of studies (van der Veen and de Boer, 2012). More recently they have been detected in outdoor air in remote locations including the Arctic (Möller et al., 2012; Salamova et al., 2014), suggesting their potential for long range atmospheric transport. Yet with only few studies reporting outdoor air concentrations, more research is needed to determine global levels/trends of these chemicals. Other compound classes to be investigated in future analysis of the GAPS-GRULAC study include inter alia polybrominated diphenyl ethers (PBDEs), non-PBDE flame retardants, polyfluoroalkyl substances (PFASs) including polyfluorooctane sulfonate (PFOS) and its precursors.

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We will also apply a newly developed method to assess the pesticide dicofol, which is a candidate for listing as a POP (Eng et al., 2016). Lastly, this paper also considers the future needs and challenges for a sustainable regional monitoring program for POPs and emerging chemicals in the GRULAC region. Challenges and recommendations are presented, including the potential role of the GAPS-GRULAC network. 2. Methodology 2.1. Sample collection and derivation of concentrations in air Sites currently operating under the GAPS-GRULAC special study network (n = 10) are shown in Fig. 1. This study addressing new and emerging POPs was initiated in 2014 and included PUF disk samplers deployed quarterly and a sorbent impregnated PUF (SIP) disk sampler deployed during 2015 to assess more volatile compounds such as penta- and hexachlorobenzene (PeCB and HCB) and linear and cyclic volatile methyl siloxanes (lVMSs and cVMS). Site and sample collection details are provided in Table 1. In 2014 only 7 sites returned samples whereas data from all 10 sites will be provided in the 2015 sampling campaign. PUF disk passive air samplers (PUF-PAS) were prepared and deployed as previously reported in Schuster et al. (2015). Briefly, PUF disks were pre-cleaned using accelerated solvent extraction (one cycle with acetone and two cycles with hexane). After drying PUF

disks were stored in 1 L pre-cleaned glass jars for shipping and for returning collected samples for analysis. PUF-PAS were sent to sites for deployment in four sampling quarters and samples were stored in a dark, cool place prior and after deployment. Field blanks were collected by following the same procedure without actual deployment of the PUF and were used to assess possible contamination from methodology and sample treatment. All samples were shipped back to ECCC for analysis. Duplicate samplers were not deployed at sites in this study, however the coefficient of variation between samplers has been determined in a previous study by Gouin et al. (2005) showing acceptable reproducibility for POPs using this type of sampler. Concentrations in air for targeted chemicals are derived from PUF disk samples by dividing the amount of chemical collected on the sampler (e.g. pg per sampler) by an effective air sample volume (Veff, m3 ). Veff is determined using the GAPS template (Harner, 2014; Parnis et al., 2016) which takes into account linear sampling and approach to equilibrium of target chemicals in PUF disks. The OPFRs are mainly associated with the particle phase in air (Shoeib et al., 2015) and have been shown to maintain linear phase sampling in PUF disks at a rate of about 4 m3/day for deployment periods of a few months (Shoeib et al., 2015; Liu et al., 2016); and so the Veff can be simply estimated as the linear phase sampling rate (4 m 3 / day) multiplied by the number of sampling days (~ 90 days) resulting in sample air volumes of approximately 360 m3. PUF disks have been shown to collect the particulate phase of air at the same rate as the

Fig. 1. The map shows the location of the 10 sites in this study and the average concentrations of selected OPFRs in air which was available for 7 of the sampling sites in the GRULAC region in 2014 only (stars represent sites involved in the study but where samples were not collected during 2014). See Table 2 for full names of OPFRs. Note, in calculation of averages where an analyte was not detected 1/2 MDL was used, providing average concentrations that are elevated when compared to individual sample concentrations provided Fig. 2.


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Table 1 Information on sampling sites (provided by collaborating institute at each site). Site ID

Location

GR03 Tapanti

Country

Type⁎

Costa Rica Colombia Mexico Mexico Colombia Brazil Brazil

Background

Latitude 9.696

Longitude −83.865

Elevation Site information [masl] 2830

Arauca Rural 7.014 −70.742 128 Sonora Agricultural 27.127 −109.840 140 Celestún Background 20.859 −90.392 52 Manizales Background 5.076 −75.437 2670 São Luis Urban −2.354 −44.124 26 São Jose Background −28.594 −49.819 1270 dos Ausentes GR27 Rio Argentina Rural −51.647 −69.207 18 Gallegos GR28 Concepción Chile Urban −36.4752 −73.0319 30 GR04 GR16 GR17 GR22 GR23 GR24

GR29 Chacaltaya

Bolivia

Background −16.21

−68.08

5240

~3 km South of Cartago (population: ~410,000) and ~20 km South East of San Jose (population: ~2.2 million), site located in Tapanti National Park ~9 km distance to the city of Arauca (population: 82,000) Valley of the Yaqui in Sonora, Benito Juárez Closest settlement is Celestún (population b 6000) ~11 km East of Manizales (population: ~400,000) Population: ~1.2 million in its metropolitan area. Site located at the city limit. ~31 km North East of São Jose dos Ausentes (population ~4000)

Population: ~98.000 in its metropolitan area, site located at the city limit The sampling site is located on the roof of the faculty of science building of UCSC (Universidad Católica de la Santísima Concepción). Population ~224,000 in its metropolitan area. Site located at the city limit. Remote air monitoring site on Chacaltaya Mountain, ~22 km from the metropolitan area of La Paz/El Alto (population 2 million), Bolivian Andes. During daytime, the planetary boundary layer reaches the station. During nighttime the site lies in the low free troposphere.

⁎ Background (BA) = sampler deployed in a remote area away from any obvious POPs sources to obtain a reference background sample; Rural (RU) = sampler deployed in a rural area, without being placed near an obvious source; Agricultural (AG) = sampler deployed in rural area cleared for farming, without being placed near an obvious source; Urban (UR) = sampled in metropolitan area, without being close to obvious sources.

gas phase hence are ideal samplers even for chemicals such as OPFRs that are primarily particle bound (Harner et al., 2013; Markovic et al., 2015). We recognize that some site-to-site variability may exist in sampling rates which are not accounted for in the current study (Petrich et al., 2013; Bohlin et al., 2014; Melymuk et al., 2014). The papers referenced above also provide additional background theory for the uptake of POPs by PUF disk samplers.

3. Sample analysis 3.1. Chemicals Details of the OPFRs analysed are listed in Table 2, along with the mass-labelled analogues used as surrogate (internal) standards and injection standard. 3.2. Extraction

Table 2 Organophosphorus flame retardants (OPFRs), their acronyms and allocations of surrogate or injection standards. Analyte

Acronym

Allocation of surrogate/injection standard

Tri-methyl phosphate Tri-ethyl phosphate Tri-n-propyl phosphate Tri-n-butyl phosphate Tris(2-chloroethyl) phosphate Tris(chloroisopropyl) phosphate Triphenyl phosphate 2-ethylhexyl diphenyl phosphate Tri-p-tolyl phosphate Tri-o-tolyl phosphate Tri-m-tolyl phosphate Tris(2-butoxyethyl) phosphate Tris(3,5-dimethyl) phosphate Tris(2-ethyl hexyl) phosphate Tris(2-isopropylphenyl) phosphate Tris(tribromo neopentyl) phosphate Tris(1,3-dichloro-2-propyl) phosphate Tris(2,3-dibromopropyl) phosphate d15 tri-ethyl phosphate d27 tri-butyl phosphate d21 tri-propyl phosphate d12 Tris(2-chloroethyl) phosphate 13 C18 Triphenyl phosphate d15 Tris(1,3-dichloro-2-propyl) phosphate d15 Triphenyl phosphate

TMP TEP TPrP TnBP TCEP TCPP TPP EHDPP p-TTP o-TTP m-TTP TBEP T35DMPP TEHP T2IPPP

d15 TEP d21 TPrP d27 TBP d12 TCEP 13

C18 TPP

3.3. Clean-up

TTBPP TDCPP

d15 TDCPP

TDBPP d15 TEP d27 TBP d21 TPrP d12 TCEP 13 C18 TPP d15 TDCPP d15 TPP

Samples were extracted using accelerated solvent extraction (ASE, ASE 350, Dionex Corporation, Sunnyvale, CA, USA). PUF-PAS were loaded into 33 mL ASE cells and fortified with 25 ng of each of the mass labelled OPFRs, used as surrogates (or internal) standards. Samples were extracted with a mixture of Petroleum Ether/Acetone (83/17, v/ v) for 2 cycles at 1500 psi under the following conditions: 50 °C, 5 min static cycle with 100% flush and 240 s purge. The extract was concentrated to 0.5 mL before a 50% split. The first half of the extract was kept as reserve and the second half underwent sample purification.

d15 TPP

Prepackaged silica columns (BondElute HF Mega BE-SI, 5 g, 20 mL, Agilent Technologies Inc.) were used for sample clean-up. The columns were pre-cleaned with 20 mL of Petroleum Ether/Acetone (1/1, v/v) and analytes eluted with 40 mL of Petroleum Ether/Acetone (1/1, v/v). The sample was then volume reduced to low volume, solvent exchanged to methanol and further reduced to a final volume of 0.5 mL under a gentle stream of nitrogen. 12.5 ng of d15-TPP was added as an injection standard (to monitor surrogate recovery) before analysis. 3.4. Analysis Separation and analysis of the target analytes was achieved using a modified previously reported method (De Silva, 2015). Separation and detection was performed with a Waters Acquity I-class Ultra Performance Liquid Chromatograph coupled with Xevo TQ-S triple quadrupole Mass Spectrometer (UPLC-MS/MS, Waters, Boston, MS). A Waters


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Acquity (Waters, Boston, MS) BEH C18 reversed phase analytical column (50 mm, 2.1 mm i.d., 1.6 μm particle size) was used for separation. A mobile phase program based upon (mobile phase A) 0.1% Formic acid in water and (mobile phase B) 0.1% Formic acid in methanol at a flow rate of 0.5 mL/min was applied for elution of the analytes; starting at 40% (mobile phase B), then increasing linearly to 62% (mobile phase B) over 1 min, increasing to 67% (mobile phase B) over 4 min, then increasing to 100% over 1 min and held for 1 min before decreasing to 40% (mobile phase B) to equilibrate the column for 1 min at initial conditions between runs. MS/MS detection, equipped with an electrospray ionization (ESI) source operated in positive ion mode, and operated in multiple reaction monitoring (MRM) mode, was used for quantitative determination of the analytes. 3.5. QA/QC The OPFRs; TMP, TEP, TnBP, TCEP, TCPP, TPP, TBEP and TDCPP were detected in the field blanks which were used for calculating analyte method detection limits (MDLs) as mean blank value +3× standard deviation. As only two field blanks were available an assumed standard deviation of 50% of the mean was used and MDLs ranged from (0.4 to 90 ng/sample). Samples were blank corrected by subtracting the mean field blank mass (ng/sample) from that in the sample. Mean concentrations for each site and for each analyte over all sites were calculated and

where target analytes were not detected, 1/2 MDL or 1/2 LOQ (a concentration corresponding to a signal:noise ratio of 10:1) were substituted. Mean surrogate recoveries (calculated from the injection standard) ranged from 30 to 40% for the mass labelled analogues and analyte concentrations were surrogate recovery corrected. 4. Results 4.1. Concentrations of OPFRs in air in the GRULAC region The OPFRs targeted in this study were well detected in GRULAC samples as shown in Table 3. We note that these results represent a preliminary look at the overall study results. Samples continue to be collected, returned and processed from participating sites and eventually a more complete picture of OPFRs and other new POPs in the GRULAC region will be developed. The most frequently detected OPFRs were TBEP, TPP, TCEP, TEP, TCPP and TDCPP with TMP, TPrP, TEHP and TnBP detected in b 50% of samples and EHDPP, TTP, T35DMPP, T2IPPP, TTBPP and TDBPP not detected. Fig. 1 shows average concentrations of OPFRs at GAPS-GRULAC sites from samples collected in 2014. TBEP, TCPP and TCEP were detected in the highest concentrations with levels ranging from b MDL to 1280 pg/m3 (mean 350 pg/m3) for TCPP; 40 to 1210 (mean 130 pg/m3) for TBEP; and bMDL to 320 (mean 130 pg/m3) for TCEP. TPP (b MDL to 130;

Table 3 Organophosphorus flame retardant (OPFR) air concentrations (pg/m3) at the seven GRULAC region sites participating in 2014. Calculated MDLs for each site are listed as “b” where the analyte was a non-detect. Sample concentrations have been blank corrected.

TMP TEP TPrP TnBP TCEP TCPP TPP EHDPP p-TTP o-TTP m-TTP TBEP T35DMPP TDCPP TEHP T2IPPP TTBPP TDBPP

Tapanti, Costa Rica (BA)

Sonora, Mexico (AG)

Q3

Q4

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

b9.4 b28 1.9 b26 71 220 b8.1 b9.3 b0.9 b0.9 b0.9 40 b0.4 2.1 b0.9 b0.4 b0.9 b0.9

13 b28 b1.9 b26 150 270 b8.1 b9.3 b0.9 b0.9 b0.9 41 b0.4 4.2 b0.9 b0.4 b0.9 b0.9

b16 b49 b3.2 b45 140 1280 70 b16 b1.6 b1.6 b1.6 130 b0.6 25 11 b0.6 b1.6 b1.6

b14 b41 b2.7 b38 150 410 130 b13 b1.3 b1.3 b1.3 110 b0.5 26 b1.3 b0.5 b1.3 b1.3

b14 b43 b2.8 b40 87 420 80 b14 b1.4 b1.4 b1.4 76 b0.5 22 b1.4 b0.5 b1.4 b1.4

b13 64 b2.5 b36 140 720 67 b13 b1.3 b1.3 b1.3 54 b0.5 21 b1.3 b0.5 b1.3 b1.3

b15 67 b2.9 b42 89 b140 23 b15 b1.5 b1.5 b1.5 89 b0.6 b0.9 b1.5 b0.6 b1.5 b1.5

b14 90 b2.7 b39 160 210 30 b14 b1.4 b1.4 b1.4 56 b0.5 29 b1.4 b0.5 b1.4 b1.4

b14 b42 25 b39 89 180 21 b14 b1.4 b1.4 b1.4 82 b0.5 b0.9 b1.4 b0.5 b1.4 b1.4

b14 b42 14 b39 130 220 26 b14 b1.4 b1.4 b1.4 120 b0.5 11 b1.4 b0.5 b1.4 b1.4

Manizales, Colombia (BA)

TMP TEP TPrP TnBP TCEP TCPP TPP EHDPP p-TTP o-TTP m-TTP TBEP T35DMPP TDCPP TEHP T2IPPP TTBPP TDBPP

Celestún, Mexico (BA)

São Luis, Brazil (UR)

São Jose, Brazil (BA)

Concepción, Chile (BA)

Q1

Q2

Q3

Q4

Q2

Q3

Q4

Q3

Q4

Q2

Q3

b13 b40 b2.6 b37 63 280 b11 b13 b1.3 b1.3 b1.3 51 b0.5 b0.8 b1.3 b0.5 b1.3 b1.3

21 61 b2.8 b39 140 320 b12 b14 b1.4 b1.4 b1.4 110 b0.6 6.2 b1.4 b0.5 b1.4 b1.4

b14 b42 b2.8 b39 70 b130 b12 b14 b1.4 b1.4 b1.4 74 b0.6 b0.9 b1.4 b0.5 b1.4 b1.4

b14 b42 b2.7 b39 240 590 b12 b14 b1.4 b1.4 b1.4 82 b0.5 b0.9 b1.4 b0.5 b1.4 b1.4

b14 b42 b2.7 b39 38 b129 110 b14 b1.4 b1.4 b1.4 70 b0.5 5.3 b1.4 b0.5 b1.4 b1.4

33 b42 b2.7 b39 360 690 52 b14 b1.4 b1.4 b1.4 110 b0.5 b0.9 b1.4 b0.5 b1.4 b1.4

b14 b42 b2.8 b39 190 430 61 b14 b1.4 b1.4 b1.4 69 b0.6 b0.9 b1.4 b0.5 b1.4 b1.4

24 b44 b2.8 b41 170 425 91 b14 b1.4 b1.4 b1.4 89 b0.6 b0.9 b1.4 b0.5 b1.4 b1.4

b13 b40 7.0 b37 b50 b120 62 b13 b1.3 b1.3 b1.3 11 b0.5 b0.8 b1.3 b0.5 b1.3 b1.3

78 61 b3.1 62 320 b150 80 b16 b1.6 b1.6 b1.6 1210 b0.6 37 b1.6 b0.6 b1.6 b1.6

100 b61 b4.0 b57 b76 b190 28 b20 b2.0 b2.0 b2.0 390 b0.8 6.2 b2.0 b0.7 b2.0 b2.0


mean 50 pg/m3) and TEP (bMDL to 90; mean 50 pg/m3) were detected at similar levels, and concentrations of TPrP, TDCPP, TMP and TnBP (TnBP only detected at Concepción, Chile) ranged from bMDL to 100 pg/m3 (means of 5, 10, 20 and 40 pg/m3 respectively), Table 3. In general the concentrations of OPFRs detected in the 4 background, 1 agricultural and 2 urban locations in the GRULAC region were in line with the few studies reporting atmospheric concentrations from other regions. The mean concentrations in air of TCPP, TCEP, TDCPP and TPP in the GRULAC region were lower (~2 to 10 times) than that reported in Toronto air, collected with high volume active air samplers in 2010–2011, (mean concentrations of 700, 580, 180 and 830 pg/m3 respectively; Shoeib et al., 2015). However, the levels were similar with that reported in the Arctic during 2010 and 2011 (high volume air sampling), with mean concentrations of 290, 280 and 20 pg/m3 for TCPP, TCEP and TPP respectively (Möller et al., 2012). Levels were also in the range of that reported around the North Sea in 2010 (high volume air sampling) with concentration ranges of 40 to 1200 pg/m3 for TCPP; 6 to 160 for TCEP; 4 to 290 for TPP and n.d. to 150 pg/m3 for TnBP (Möller et al., 2011). TBEP was lower in both of these studies than that detected in the GRULAC area with levels ranging n.d. to 10 pg/m3 in the Arctic and n.d. to 80 pg/m3 in the North Sea. Salamova et al. (2014) also reported Arctic atmospheric particle concentrations of OPFRs with mean concentrations of 20, 20, 60 and 60 pg/m3 for TCEP, TPP, TCPP and TDCPP respectively. Higher TBEP concentrations were seen (50 to 200 pg/m3) that were more in line with that seen in the GRULAC region, than that reported by Möller et al. (2011 and 2012). Concentrations of TCPP, TPP and TnBP were higher in background air from North Finland in 2004 (Marklund et al., 2005), sampled with a high volume sampler, with concentrations of 810, 12,000 and 280 pg/m3 respectively, however TDCPP (20 pg/m3) was in line with results for the GRULAC region in the current study. Concentrations in the GRULAC were also similar to that reported above the Mediterranean and Black Seas (Castro-Jiménez et al., 2014), high volume sampling, for TCPP, TPP and TDCPP (130 to 2700, n.d. to 80 and n.d to 460 pg/m3 respectively). However levels of TCEP, TnBP and TEHP were up to 10 times higher above the Mediterranean and Black Seas (70–2400, 60–600, and 40– 300 pg/m3 respectively). The study by Castro-Jiménez also reported higher ΣOPFR concentrations at locations where a 3 day air mass back trajectory indicated the air had circulated over urban cities such as Alexandria, Egypt, suggesting that large coastal cities are a source of atmospheric OPFRs to this region. TCEP was reported at the Black Sea at much higher concentrations than the Mediterranean, indicating different sources for TCEP, whereas the other OPFRs were of similar concentrations between the two seas. Similarly, the study by Cheng et al. (2013), which used high volume samplers to report OPFRs in aerosols in the West Pacific, Indian and Southern Ocean atmosphere, saw higher concentrations of TBEP, TCEP, TCPP, TDCPP near populated regions in Australia, New Zealand and China, implying that populated areas are strong pollutions sources of OPFRs to oceanic atmosphere. The elevated concentrations near these countries were of a similar level to that seen in the GRULAC region with concentrations of 30 to 95, 50 to 130 and n.d. to 9 pg/m3 for TBEP, TCEP and TCPP respectively. TDCPP however exceeded the GRULAC levels at the sites near Australia and China, with 370 and 830 pg/m3 reported. Although all these studies have deployed active air samplers for measuring OPFR concentrations in air, it has been previously reported that there is generally good agreement between passive and active air sampling for POPs, hence they are comparable methods (Ahrens et al., 2013; Markovic et al., 2015). More recently an uptake study of OPFRs has shown comparability between passive and active air samplers with the OPFRs remaining in the linear uptake region during deployment of PUF-PAS (Jantunen et al., 2015). In the three sites that returned PUF-PAS for all four sampling quarters no seasonal trends were determined and the OPFR profile for each sample received from the 7 GRULAC sites is presented in Fig. 2 below. The one agricultural site at Sonora, Mexico and the urban site São Luis, Brazil both had concentrations within the same range as the other 4

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background sites. However the urban site, Concepción Chile, had the highest ΣOPFR concentrations (~double the other sites) and the profile differed at this location with TBEP dominating (as compared to TCPP dominating at the other sites). This suggests different sources of OPFRs to the atmosphere at this sampling location. For instance possible sources include a local airport a few kilometers from the site as well as heavy traffic associated with the city and with the university where the sampler is located. Although an assessment of all potential sources to urban areas is beyond the scope of this project deployment of multiple samplers (at different location in the area) as well as samplers ‘down-wind’ of possible sources would be informative to assessing emissions to air. The authors note however that there were inconsistencies in the sampling of this site, namely samples were returned wrapped in foil and placed in plastic zip lock bags (instead of the provided 1 L precleaned glass jars) and a field blank was not provided for this site. OPFRs are used extensively as plasticisers hence the sampling protocols avoid contact with plastic products where possible as they may be contamination sources. Future analysis of the PUF-PAS deployed in 2015 at this site and at additional GRULAC sites will provide more information on profiles and possible trends. Although these inconsistencies in sample collection described above are not ideal, they highlight the importance of communication in a large collaborative study such as the GAPS Network, including clear protocols for sample deployment and collection, to ensure sample consistency among sites and avoiding possible contamination sources. 4.2. Outlook for POPs monitoring in the GRULAC region According to the UNEP guidance document for the GMP, regional air monitoring networks should comprise of a small number of long-term active air sampling sites and be supplemented with a larger number of passive air sampling sites to enhance spatial coverage (UNEP, 2007; Klanova and Harner, 2013). Based on this guidance, the GRULAC should strive for 2–3 high volume air sampling stations and ~15 or more passive air sampling stations. Ideally, and to ensure comparability, these data should be coordinated and delivered by a single laboratory. Note that this regional arrangement does not preclude the existence of a larger number of passive sampling stations throughout the region to fulfill research or national monitoring efforts. However, the regional network should focus on sustaining a selected number of core sites for long term reporting under the GMP. The 2nd regional report for the GRULAC region (UNEP, 2016a) identified that there was currently no long term high volume station for POPs in the region and called for the need for a long term station(s). Results for POPs in air from passive samplers were available and reported in the 2nd GRULAC GMP report through the GAPS Network, LAPAN and the GEF-funded project, however, temporal trends for POPs in air were not yet established. There are numerous challenges with implementing a new regional air monitoring program for POPs in the GRULAC region. Some of the major ones include: i.) Identifying a central laboratory and expert(s) to coordinate the regional network, including analysis and preparation of data reported to the GMP. Currently, data that are provided by GAPS, LAPAN and GEF-funded studies are compiled by the Regional Organization Group (ROG) members for the GRULAC region, for reporting to the GMP. There is an opportunity to better harmonize these data and monitoring activities and to move towards a longer term, sustainable regional network that is well integrated. ii.) The need to address the reporting needs for a growing list of POPs and candidate POPs. This is a major analytical and resource pressure for all long-term air monitoring programs as chemicals continue to be listed under the Convention. It is increasingly difficult for laboratories to develop expertise and reliable analysis

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Fig. 2. OPFR profile in each sample returned from the seven GRULAC sites participating in 2014. The entry of ‘ns’ indicates no sample was returned for that particular quarter.

methods for all listed and candidate POPs. Although not a requirement under the Convention, the availability of monitoring data on candidate POPs is very useful for the risk assessment work of the POPRC and for potentially establishing baseline levels of future POPs prior to their listing. iii.) Related to the reporting challenges for a growing list of POPs is the need to interpret what these data mean. This interpretation is best performed using an ‘integrated approach’ that includes information on sources and emissions of the targeted POPs as well as models that can describe long-range transport and source receptor relationships (UNEP, 2007). This complementary information is needed to assess spatial and temporal trends in the data and to account for secondary sources and climate- and meteorology-related effects that can result in changes in levels of POPs in air. The “integrated approach” can also inform the process of selecting representative sites for a regional monitoring program (UNEP, 2007). iv.) The need to ensure regional and global consistency and comparability of passive sampling data. As new passive sampling strategies are implemented in the region (e.g. GAPS, LAPAN, GEF projects and other initiatives) it will be important to integrate and harmonize these data for reporting to the GMP. This includes meshing with the older data from GAPS sites that have been operating since 2005. v.) Improving the link/understanding of POPs in air and health. This is central to the main objective of the Stockholm Convention,

which is to protect human health and the environment from the harmful effects of POPs. To achieve this objective it may not be sufficient to measure and show that trends of listed POPs are declining. This is because the listed POPs comprise only a small subset of toxic chemicals that are present in air. Therefore it is important to develop strategies that can link air monitoring in support of the GMP to health effects by assessing the toxicity of the entire air mixture of organic chemicals and how this is changing over time.

4.3. Recommendations for implementation of a regional network Based on the challenges identified above for implementing a sustainable GRULAC region POPs monitoring network for the GMP, the following recommendations are made. i.) GRULAC region experts on POPs air monitoring should work with ROG members to address the needs of reporting under the GMP and in developing a strategy for a sustainable long term program. If possible, one or perhaps a few regional labs/experts should be nominated to lead the work. This will help to ensure quality of data and comparability of data for establishing long term trends. ii.) Partnerships should be developed within the GRULAC region and with international expert labs/programs to deal with the challenges of the growing list of POPs. This could be realized through


sharing extracts, analytical methods and other guidance on new POPs. The GAPS Network could continue to provide some of these functions moving forward, for instance through the current GAPS-GRULAC study targeting new POPs. Sample archiving is another consideration that will help to ensure completeness of data as analytical methods in the region are developed in the future for some of the more challenging POPs. Retrospective analysis of archived samples has shown to be effective under the GAPS Network for addressing analytical challenges with emerging contaminants and candidate POPs (Eng et al., 2016; Lee et al., 2016). iii.) A regional monitoring strategy for the GRULAC region should include a plan for interpreting the data using an “integrated approach” that includes emissions information and models. This will improve understanding of the observed spatial and temporal trends in the data and better inform risk assessment and risk management efforts, as well as the selection of representative monitoring sites. iv.) For any regional strategy that is eventually developed and implemented in the GRULAC region, it will be important to harmonize data originating from different sources/programs (e.g. GAPS, GEF, LAPAN etc.). Regional intercalibration studies should be implemented to ensure data comparability on a regional scale. Global-scale intercomparability can be achieved through participation in UNEP-led international intercalibration exercises (UNEP, 2010) and also by co-location of sampling sites with global-scale programs such as GAPS. The long-term role of the GAPSGRULAC program (e.g. required number of long term sampling sites) will also need to be considered and will depend on the regional strategy that is developed and implemented for long-term monitoring under the GMP. v.) Improving linkages to air monitoring and health effects can be done through the application of in vitro assays to passive air sample extracts (i.e. entire mixtures of organics). These assays are becoming increasingly sensitive, can account for synergism and antagonism, and can test for different types of toxicity indicators (e.g. mutagenicity, cytotoxicity, genotoxicity, estrogenic and androgenic effects). Thus passive air sampling programs are an ideal platform for mapping different toxicity indicators in air over a regional scale and following these trends over time.

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