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Assessing PCDD/Fs in air across Latin American countries using PUF disk passive air samplers Jasmin Katharina Schuster, Tom Harner, Gilberto Fillmann, Lutz Ahrens, Jorgelina Cecilia Altamirano, Wanderley Rodrigues Bastos, Luisa Eugenia Castillo, Johana Cortés, Oscar Fentanes, Alexey Gusev, Maricruz Hernandez, Martin Villa Ibarra, Nerina Belén Lana, Sum Chi Lee, Ana Patricia Martínez, Karina Miglioranza, Andrea Padilla Puerta, Federico Segovia, May Siu, Maria Yumiko Tominaga, and Beatriz Helena Aristizábal Zuluaga Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/es506071n • Publication Date (Web): 16 Feb 2015 Downloaded from http://pubs.acs.org on February 18, 2015

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Environmental Science & Technology

Assessing PCDD/Fs in air across Latin American countries using PUF disk passive air samplers Jasmin K. Schuster‡, Tom Harner‡*, Gilberto Fillmannβ, Lutz Ahrens‡, Jorgelina Cecilia Altamiranoθ, Wanderley Bastos∫, Luisa Eugenia Castillo♦, Johana Cortésα, Oscar Fentanes∇, Alexey Gusevε, Maricruz Hernandez•, Martín Villa Ibarraϒ, Nerina Belén Lana⊗, Sum Chi Lee‡, Ana Patricia Martínez∇, Karina S. B. Miglioranzaδ, Andrea Padilla Puerta∞, Federico Segovia•, May Siu◊, Maria Yumiko Tominagaγ, Beatriz Helena Aristizábal Zuluagaα

‡ Air Quality Processes Research Section, Environment Canada, Toronto, ON M3H 5T4, β Universidade Federal do Rio Grande, Instituto de Oceanografia, Rio Grande - RS, Brazil, θ Facultad de ciencias exactas y naturales, Universidad Nacional de Cuyo, Mendoza, Argentina, ∫ Laboratório de Biogeoquímica Ambiental, Universidade Federal de Rondônia, Porto Velho, Brazil, ♦ Central American Institute for Studies on Toxic Substances, Heredia, Costa Rica, α Universidad Nacional de Colombia, Manizales, Colombia, ∇ CENICA/INE, Naucalpan de Juárez, Mexico, ε Meteorological Synthesizing Centre-East (MSC-E), Moscow, Russia, • Ministerio del Ambiente de Ecuador, Quito, Ecuador, ϒ Instituto Tecnológico Superior de Cájeme, Cájeme, Sonora, México, ⊗ Laboratorio de Química Ambiental, Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales-CONICET, Mendoza, Argentina, δ Universidad Nacional Mar del Plata, CONICET, Mar el Plata , Argentina, ∞ Universidad Nacional de Colombia, Arauca, Colombia, ◊ Atmospheric Science & Technology Directorate, Environment Canada, Ottawa, ON K1A 0H3, γ CETESB, São Paulo, Brazil *corresponding author: [email protected]; tel. +1 416 739 4837

Word Count: Word count of tables: Word count of figures: Total:

~3400 ~300 ~1200 ~4900

Keywords: PCDD/Fs, GRULAC, air monitoring Brief: Assessing concentrations in air of PCDD/Fs in the GRULAC region to fill data demands under the Stockholm convention.

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Abstract

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A passive air sampling network has been established to investigate

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polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) at

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Global Atmospheric Passive Sampling (GAPS) sites and six additional sites in the Group of

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Latin American and Caribbean Countries (GRULAC) region. The air sampling network

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covers background, agricultural, rural and urban sites. Samples have been collected over

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four consecutive periods of 6 months, which started in January 2011 (period 1 (January

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2011 – June 2011), period 2 (July 2011 – December 2011), period 3 (January 2012 – June

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2012) and period 4 (July 2012 – January 2013)). Results show that: i) the GAPS passive

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samplers (PUF disk type) and analytical methodology are adequate for measuring

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PCDD/F burdens in air, and ii) PCDD/F concentrations in air across the GRULAC region

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are widely variable by almost two orders of magnitude. The highest concentrations in air

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of Σ4-8PCDD/Fs was found at the urban site São Luis (Brazil, UR) (i.e. 2560 fg/m3)

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followed by the sites in São Paulo (Brazil, UR), Mendoza (Argentina, RU) and Sonora

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(Mexico, AG) with 1690 fg/m3, 1660 fg/m3 and 1610 fg/m3, respectively. Very low

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concentrations of PCDD/Fs in air were observed at the background site Tapanti (Costa

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Rica, BA) with 10.8 fg/m3. This variability is attributed to differences in site

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characteristics and potential local/regional sources as well as meteorological influences.

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The measurements of PCDD/Fs in air agree well with model predicted concentrations

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performed using the Global EMEP Multi-media Modeling System (GLEMOS) and emission

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scenario constructed on the basis of the UNEP Stockholm Convention inventory of dioxins

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and furans emissions.

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Introduction

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Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF)

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are recognized as persistent organic pollutants (POPs) due to their properties of

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persistence, potential to bioaccumulate and inherent toxicity to wildlife and humans1.

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Although PCDD/Fs are restricted under the Stockholm Convention on POPs, they are still

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emitted unintentionally from numerous sources as by-products of chemical

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manufacturing, incineration and other combustion-related activities2. This makes the

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estimate of PCDD/Fs inventories and burdens more challenging compared to other

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chemicals. The unintentional production of PCDD/Fs as by-products during the

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production of other chemicals (i.e. polychlorinated biphenyls, pentachlorophenol,

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trichlorobenzene) and in industrial processes involving chloro-organic compounds (i.e.

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pulp and paper industry) used to be a major source, leading to PCDD/Fs emissions via

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contamination products (i.e. pentachlorophenol-treated wood, leather, textiles) and

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emissions directly to water and soil. Stricter legislation and the introduction of new

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processes reduced these sources significantly in most countries1. Nowadays thermal

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processes are the major sources of PCDD/Fs to the air e.g. municipal solid waste

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incineration (MSWI) with PCDD/Fs associated with fly and bottom ash. While the

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PCDD/Fs emissions from MSWI has been reduced in recent years through optimizing

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incineration conditions, this still provides the major contribution to the total PCDD/Fs

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emissions in most countries1.

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Under Article 16 of the Stockholm Convention, dealing with its Effectiveness

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Evaluation, there is a need to measure PCDD/Fs in air under a regionally based Global

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Monitoring Plan (GMP). Air is one of two core media targeted under the GMP (human

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tissues being the other). The measurements in air should include both temporal and

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spatial resolution in order to evaluate effectiveness of control measures and to provide

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information on the long-range transport of PCDD/Fs. Air monitoring data for PCDD/F

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from national networks are available for Northern America from the Canadian National

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Air Pollution Surveillance network (NAPS), the U.S. National Dioxin Air Monitoring

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Network (NDAMN) and the Mexican Dioxin Air Monitoring Network (MDAMN) 3.

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In the first GMP report submitted in 2009, it was recognized that information on

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PCDD/Fs in air in the Group of Latin American and Caribbean States (GRULAC) were

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lacking. Fiedler (2007) recently published a review of PCDD/Fs emission estimates

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provided to UNEP by participating countries. 4 The review highlighted MSWI as the main

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PCDD/F source to air, followed by open burning processes, and heat and power

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generation. The UNEP global emission inventory for PCDD/Fs was used to link emissions

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to a country’s economic status5 and in the Global EMEP Multi-media Modelling System

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(GLEMOS) to estimate global PCDD/F concentrations in air6.

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Thus the objective of this project was to further assess the suitability of the

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Polyurethane foam (PUF) disks passive air sampler for PCDD/Fs and to address this data

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gap and implement an air monitoring network for PCDD/Fs that can deliver baseline

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information on PCDD/Fs in air. It will also serve as a baseline against which future

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concentrations in air can be compared so as to inform on the ‘Effectiveness’ of the

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Stockholm Convention on POPs on reducing levels of PCDD/Fs in air in the GRULAC

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region.

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Method

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Study Design

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The compounds targeted in this study are the tetra (TCDD/Fs), penta- (PeCDD/Fs),

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hexa- (HxCDD/Fs), hepta- (HpCDD/Fs) and octa-chlorinated (OCDD/Fs) dibenzo-p-

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dioxins/furans. Results are reported as the sums of the homologue groups as well as the

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17 individual 2,3,7,8 chloro-substituted PCDD/Fs (2,3,7,8-TCDF, 1,2,3,7,8-PeCDF,

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2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, 2,3,4,6,7,8-HxCDF, 1,2,3,7,8,9-

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HxCDF, 1,23,4,6,7,8-HpCDF, 1,2,3,4,7,8,9-HpCDF, OCDF, 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD,

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1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 1,2,3,7,8,9-HxCDD, 1,2,3,4,6,7,8-HpCDD, OCDD).

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Passive air samples were collected during the period from January 2011 – March

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2013 at 13 sites in six South American countries (Mexico, Costa Rica, Ecuador, Colombia,

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Brazil, Argentina). The sampling sites spanned a longitude of 44–110 °W and a latitude

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of 52 °S–27 °N. The average temperatures at the sites during the deployment period

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ranged from 7.6 °C at the most Southern site to 25.8 °C at the Northern sites. The

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sampling sites were classified as “background” (BA, n = 6), “agricultural” (AG, n = 1),

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“rural” (RU, n = 3) and “urban” (UR, n = 3) depending on land use and population

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density. The sampling periods were about 6 months and the consecutive samples

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collected per site vary (n = 1–4) (period 1 (January 2011 – June 2011), period 2 (July

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2011 – December 2011), period 3 (January 2012 – June 2012) and period 4 (July 2012 –

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January 2013)). The sampling period of 6 months ensures a higher effective sampling

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volume for PCDD/Fs and allows for a higher accumulation of the target chemicals on the

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sampling medium in background areas. Supplementary information (SI) Figure 1 and SI

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Tables 1 and 2 summarize information on the sites that comprise the PCDD/F passive air

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monitoring network.

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Pre-cleaning procedure for passive sampling media

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PUF disks were pre-cleaned using Accelerated Solvent Extractor (ASE) (1 cycle of 200 mL

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acetone and 2 cycles of 200 mL hexane) and dried under ultra high purity (UHP) grade

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nitrogen in a vacuum oven at 30 - 40°C. PUF disks were stored in 1 L amber jars for

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shipping.

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Sample Collection

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A sampling kit including a sampling protocol, pre-cleaned PUF disks and passive

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sampler housing was shipped from Environment Canada to the participating partners on

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site. Details to the sampling process can be found in the sampling protocol in the SI Text

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1. In short, sampler housing was installed at a minimum of 2 m from the ground in

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unobstructed air flow. PUF disks were installed and removed from the sampler housing

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using clean forceps. Sampling media was stored at a dark and cool place prior to and

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after deployment. Field blanks (n = 14) were collected by following the same steps as for

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the air samples but without actual deployment. The field blanks are used to assess

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possible contamination associated with the methodology and sample treatment.

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Samples were returned to Environment Canada for analysis.

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Extraction and analysis

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PUF disks were spiked with a known amount of isotopically labelled surrogate

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standards (13C12-TCDD, 13C12-TCDF, 13C12-PeCDD, 13C12-PeCDF, 13C12-HxCDD, 13C12-HxCDF,

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13

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Laboratories Inc., Guelph, Ontario) and then extracted with toluene by Soxhlet

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apparatus for 16-20 hours. After extraction, samples were cleaned up using column

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chromatography with an acid/base column followed by an activated alumina column.

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The fraction containing the PCDD/Fs was eluted with dichloromethane (DCM)/hexane

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(50/50, v/v) and blown down to dryness. A known concentration of internal standard

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(13C12-1,2,3,4-TCDD and

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chromatography (GC)/high resolution mass spectrometry (Agilent 6890 and Waters

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MicromassAutoSpecUltima HRMS). Samples were analysed with electron impact

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ionisation in selective ion mode on a 60 m DB-5 column (0.25 mm ID, 0.25 μm film

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thickness). Samples were injected in splitless mode (injector temperature of 290°C) with

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helium as the carrier gas. The GC oven temperature program began at 100 °C for 1 min

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and was increased by 35 °C/min to 200 °C, then by 4 °C/min to 280°C, where it was held

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for 15 min and then by 10 °C/min to 300 °C, where it was held for 5 min 3, 7.

C12-HpCDD,

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C12-HpCDF,

13

13

C12-OCDD, all standards were supplied by Wellington

C12-1,2,3,7,8,9-HxCDD) was added prior to analysis by gas

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Quality assurance and quality control QA/QC

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Results for field blanks and method recoveries are presented in SI Tables 3 and 4.

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Average recoveries of surrogates ranged from 93%–103% and analysis of field blanks

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showed no major contamination issues, with most PCDD/Fs falling below instrumental

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detection limit in field blanks. The method detection limit (MDL) was calculated as the

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average concentration of the field blanks plus 3 times standard deviation of the field

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blanks. The MDL is reported in SI Table 3. For data interpretation values below MDL

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were replaced by 2/3*MDL.

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Global EMEP Multi-media Modelling System (GLEMOS)

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PCDD/F air concentrations for the sampling sites were estimated using GLEMOS and the

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UNEP Stockholm Convention emissions inventory of dioxins and furans. Details on

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GLEMOS and the emission inventory are discussed by Gusev et al. 6, 8

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Results and Discussion

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Passive air sampling basics for PCDD/Fs

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PCDD/Fs are semi-volatile compounds and at ambient temperatures most of the

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PCDD/Fs are associated with the particle-phase rather than the gas - phase due to their

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low volatility9. At the temperatures observed during the study only the lighter

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homologue groups (TCDFs, PeCDFs, TCDDs) will be found predominately in the gas-

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phase10. A recent analysis of PUF disks samplers for the uptake of the mostly particle

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bound polycyclic aromatic hydrocarbons indicates that particle-phase compounds are

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captured at similar rates as the gas-phase compounds11, 12. Mari et al. (2008) published

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data on PCDD/Fs acquired simultaneously by passive and active air sampling. Average

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PCDD/F sampling rate values estimated from concentrations in the combined gas and

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particle-phase were more realistic (2.0 m3/day) than values estimated solely from the

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gas phase concentration (25 m3/day)13.

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The conversion to concentration in air basis involves the derivation of effective air

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sample volumes as is done under the GAPS Network14,

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assumed for the PCDD/Fs for the entire sampling period due to their low volatility.

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Therefore the equivalent air volume is simply the product of the linear gas-phase

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. A linear uptake can be

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sampling rate of the PUF disks sampler (i.e. ~4 m3/day) and the deployment time (e.g.

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180 days for a 6-month deployment). This results in an effective air sample volume of

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about 720 m3.

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Monitored PCDD/F concentrations in air

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Σ4-8PCDD/F concentrations (average, minimum, maximum) in air are summarized in

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Table 1. Concentrations in air observed during the 6 month deployment periods are

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reported in the SI Table 5. The highest concentrations in air of Σ4-8PCDD/Fs were at the

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urban site São Luis (Brazil, UR) (i.e. 2560 fg/m3) while the lowest concentrations were at

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the background site Tapanti (Costa Rica, BA) with 10.8 fg/m3. Correlations were carried

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out between the observed PCDD/F concentrations in air and site specific properties such

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as land use, latitude and average temperatures. No significant trends were observed.

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This suggests that PCDD/F concentrations in air are more likely associated with local

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sources.

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At the majority of sites two consecutive 6-months samples were collected. There

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was no substantial difference between the sampling periods at the individual sites. The

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PCDD/F data from the sites Sonora (Mexico, AG), Yucatan (Mexico, BA), Manizales

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(Colombia, BA) and Arauca (Colombia, RU) is available for all four sampling intervals

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between January 2011 – December 2012. No substantial differences or seasonal trends

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were observed between the PCDD/F concentrations in air for the different 6-month

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sampling periods at the individual sites (Figure 1 fore Sonora and SI Figure 2 for Yucatan,

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Manizales and Arauca). Other studies have reported seasonal variations for PCDD/F

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concentrations in air between winter and summer seasons10,

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month sampling periods in the current study span both winter and summer months and

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so no seasonal variations are expected.

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. However, the 6-

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The toxic equivalent (TEQ) values were calculated for the 17 most toxic 2,3,7,8-

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chloro-substituted PCDD/Fs using international toxic equivalency factors (TEFs) 1. The

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highest monitored TEQ values were found for 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF with

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average values of 3.2 fg TEQ/m3 (0.10–12 fg TEQ/m3) and 3.0 fg TEQ/m3 (0.13–14 fg

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TEQ/m3) respectively. The values for Σ17TEQ PCDD/Fs ranged from 0.7–43 fg TEQ/m3with

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the highest concentrations observed at São Luis (Brazil, UR), and the lowest quantifiable

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data at Salta (Argentina, BA). Average values for Σ4-8PCDD/Fs are reported in Table 1.

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Values monitored at Tapanti for the individual 2,3,7,8 chloro-substituted were all

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below MDL. The concentration trends for the Σ17TEQ PCDD/Fs values mirrors the trends

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observed for the total Σ4-8PCDD/F concentrations in air with the higher values of 30 fg

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TEQ/m3, 24 fg TEQ/m3 and 24 fg TEQ/m3monitored at São Paulo (Brazil, UR), Mendoza

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(Argentina, RU) and Sonora (Mexico, AG) respectively. Figure 2 shows the distribution of

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the average TEQ concentrations in air for the individual congeners at all sites.

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Comparison to PCDD/Fs levels published in other studies

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The TEQ values observed for the GRULAC region in this study are in the same order

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of magnitude as other concentrations in air reported in recent studies. Bogdal et al.

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(2013) reported concentrations derived from passive samplers deployed between 2010

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and 2011 in the GRULAC region –ranging from 9–678 fg TEQ/m3 18, 19. As two sites that

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were monitored in the 2010–2011 study were also used in the present study, a direct

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comparison of the observed concentrations in air is possible. Bogdal et al. (2013)

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published monitoring results as sample loads (pg/PUF), which were here converted to

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concentrations in air for comparison reasons by applying the sampling rate of 4 m3/day

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resulting in derived average TEQ concentrations for São Paulo (Brazil, UR) and Quito

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(Ecuador, UR) of 34 fg TEQ/m3 and 5.3 fg TEQ/m3. These are within a factor of two of

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results from the present study of 25 fg TEQ/m3 (January 2012 – December 2012) and 3.6

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fg TEQ/m3 (January 2011 – December 2011), respectively. The present study observed

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an average concentration in air of 4.6 fg TEQ/m3 between January 2011 – December

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2012 at the background site Manizales (Colombia, BA) in a nature reserve 11 km from

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the city limits, whereas Aristizábal et al. (2011) reported values between 1–52 fg

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TEQ/m3 for 2009–2010 at an urban site in Manizales 20. The MDAMN study site Celestún

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at Yucatan is identical with the site in this study. MDAMN applied active air samplers

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and results from 2011 - 2012 show a PCDD/F concentration in air for four 6-day samples

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ranging from 5.6 – 26 fg TEQ/m3. With the exception of one unusually high value

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reported by MDAMN for February 2012, the 6 months integrated PCDD/F

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concentrations from the present study that range from 5.7 - 8.2 fg TEQ/m3 are in the

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same range as the MDAMN values 3.

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Other studies reported a wide range of PCDD/F concentrations in air for other areas

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around the world. Bogdal et al. (2013) reported concentrations in air ranging from 18–

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532 fg TEQ/m3 and 1–87 fg TEQ/m3 for Africa and the Pacific Islands respectively 19. For

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Europe recent values were reported for Catalonia, Spain with 17–348 fg TEQ/m3 (for

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1994–2002 for 28 sites, Abad et al. (2004) 21), for Barcelona, Spain with 11–39 fg TEQ/m3

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(2005, Mari et al. (2008) 13), for Italy with 2.9–65 fg TEQ/m3 (2000–2001, Menichini et al.

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(2007)

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(2014) 16) and for the UK as < 50 fg TEQ/m3 (2005 – 2008, Katsoyiannis et al. (2010)23). Li

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et al. (2011) reported concentrations in air of 1–145 fg TEQ/m3 in Anshan, Northeast

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China for 2008–2009 17.

22

), for Zurich, Switzerland with 11–190 fg TEQ/m3 (2010–2011, Bogdal et al.

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Comparison to modelled PCDD/Fs levels

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Measured PCDD/F air concentrations in the GRULAC region were compared with the

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results of a pilot modelling study, performed using the Global EMEP Multi-media

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Modeling System (GLEMOS) and emission scenario constructed on the basis of the UNEP

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Stockholm Convention inventory of dioxins and furans emissions6, 8. Model predictions

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obtained for 2012 were in a reasonable agreement with measured air concentrations.

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For more than a half of the sites modelled values were within a factor of two with

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measurements and found to correlate with observed levels (Figure 3.). Some sites

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showed higher concentrations than predicted by the model, especially for some of the

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rural and urban sites (e.g. São Luis, Mendoza). The highest difference was obtained for

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the site Rio Gallegos (more than an order of magnitude), which is likely caused by the

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uncertainties in spatial distribution of PCDD/F emissions. The model used population

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densities for the estimations of the PCDD/F emissions grid and possibly underestimated

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local PCDD/F sources.

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PCDD/F homologue distribution

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The PCDD/F homologue contributions to Σ4-8PCDD/F can be an indication of the

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origin of the emissions and/or reflect weathering after emission. In general, the most

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dominant PCDD/Fs in the present study were OCDD and 2,3,7,8-TCDF with average

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concentrations of 35 fg/m3 and 30 fg/m3, respectively. This agrees with the general

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pattern reported for the 2,3,7,8-substituted PCDD/Fs in air

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concentrations in air were previously explained by a lower atmospheric removal rate

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compared to other PCDDs.

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dominant PCDD/Fs homologues that are released during biomass burning.

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from more industrial emission profiles and might be related to ongoing deforestation

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processes in some countries of the GRULAC region. The PCDF congeners show

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decreasing concentrations in air with increasing degree of chlorination; whereas PCDDs

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show increasing concentrations in air with increasing degree of chlorination (Figure 4).

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This pattern was observed in PCDD/F air sampling campaigns carried out with both

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passive and active samplers, which is further evidence that the PUF disk sampler is

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suitable for monitoring both gas- and particle - phase PCDD/Fs 10.

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24

10, 13

. Higher OCDD

Gullett and Tuoati also reported OCDD and TCDFs as the 25

This differs

In general, the relative contributions of the individual PCDD/F congeners to Σ4-

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8PCDD/F

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Manizales (Colombia, BA), Arauca (Colombia, RU) and São Luis (Brazil, UR) exhibited

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consistently mass% (2,3,7,8-TCDF) > mass% (OCDD), which sets their congener pattern

were consistent for most sites in the present study. However, the three sites

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apart from the other sites in this study. This likely reflects a different dominant PCDD/F

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emission source for these three sites compared to the other sites in this study.

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Overall there was no shift in the PCDD/F contributions between the different sampling

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periods at the individual sites.

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The ratio of ΣPCDDs/ΣPCDFs ranged from 0.18–1.2 which is within the reported range of 0.13–21 10.

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Implications

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This study is among the first to report concentrations of PCDD/Fs in air in South

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America. In addition to establishing baseline data for air across the region, the study

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establishes a suitable monitoring network for PCDD/Fs that is based on the GAPS

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Network and the PUF disk passive air sampler. This cost effective approach is a model

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that can be used in other regions to assess spatial and temporal trends of PCDD/Fs for

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reporting under the Global Monitoring Plan of the Stockholm Convention on POPs.

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Furthermore the study demonstrates how the results from passive samplers can be

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integrated with emission inventories and models to better assess the effectiveness of

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control measures.

328 329

Acknowledgement

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We would like to thank UNEP for funding, our collaborators at the GRULAC sampling

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sites and Jean-Pierre Charland and Gary Poole of the NAPS Network for analytical

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support. Field work in Mendoza, Argentina was supported by Consejo Nacional de

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Investigaciones Científica y Técnicas, Agencia Nacional de Promoción Científica y

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Tecnológica, Universidad Nacional de Cuyo, Organization for Prohibition of Chemical

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Weapons and Pierre Auger Observatory. We also thank Ramon Guardans for useful

336

discussions. G. Fillmann was sponsored by the Brazilian Research Council (CNPq PQ

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312341/2013-0).

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338 339

Supplementary information

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Supplementary information is available for this publication. The SI contains individual

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PCDD/Fs data observed in this study, information on the sampling sites and the

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sampling protocol provided to the participants of this study. This information is available

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free of charge via the Internet at http://pubs.acs.org/ .

344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375

References 1. Fiedler, H., Dioxins and furans (PCDD/PCDF). In Persistent Organic Pollutants, Springer: 2003; pp 123-201. 2. Lee, W.-S.; Chang-Chien, G.-P.; Wang, L.-C.; Lee, W.-J.; Tsai, P.-J.; Wu, K.-Y.; Lin, C., Source identification of PCDD/Fs for various atmospheric environments in a highly industrialized city. Environmental science & technology 2004, 38, (19), 4937-4944. 3. Wöhrnschimmel, H.; Yao, Y. Assessing Comparability of Atmospheric PCDD, PCDF and Coplanar PCB Data from North American Ambient Air Monitoring Networks 2014-09-01, 2014. 4. Fiedler, H., National PCDD/PCDF release inventories under the Stockholm Convention on Persistent Organic Pollutants. Chemosphere 2007, 67, (9), S96-S108. 5. Cao, Z.; Fiedler, H.; Wang, B.; Zhang, T.; Yu, G.; Huang, J.; Deng, S., Economic status as a determinant of national PCDD/PCDF releases and implications for PCDD/PCDF reduction. Chemosphere 2013, 91, (3), 328-335. 6. Gusev, A.; Rozovskaya, O.; Shatalov, V.; Aas, W.; Nizzetto, P. Persistent Organic Pollutants in the Environment; Meteorological Synthesizing Centre East, Norwegian Institute for Air Research (NILU): 2014. 7. Dann, T., Ambient Air Measurements of Polycyclic Aromatic Hydrocarbons (PAH), Polychlorinated Dibenzo-p-Dioxins (PCDD) and Polychlorinated Dibenzofurans in Canada (1987-1997). Le Centre, Environnement Canada.: 1998. 8. Gusev, A.; Shatalov, V.; Rozovskaya, O., Pilot Modelling of PCDD/F Transport and Fate on Global Scale and within the European Region. Organohalogen compounds In press. 9. Harner, T.; Green, N. J.; Jones, K. C., Measurements of octanol-air partition coefficients for PCDD/Fs: A tool in assessing air-soil equilibrium status. Environmental science & technology 2000, 34, (15), 3109-3114.

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Environmental Science & Technology

376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418

Page 14 of 21

10. Lohmann, R.; Jones, K. C., Dioxins and furans in air and deposition: a review of levels, behaviour and processes. Science of the Total Environment 1998, 219, (1), 53-81. 11. Harner, T.; Su, K.; Genualdi, S.; Karpowicz, J.; Ahrens, L.; Mihele, C.; Schuster, J.; Charland, J.-P.; Narayan, J., Calibration and application of PUF disk passive air samplers for tracking polycyclic aromatic compounds (PACs). Atmospheric Environment 2013, 75, 123-128. 12. Eng, A.; Harner, T.; Pozo, K., A Prototype Passive Air Sampler for Measuring Dry Deposition of Polycyclic Aromatic Hydrocarbons. Environmental Science & Technology Letters 2013, 1, (1), 77-81. 13. Mari, M.; Schuhmacher, M.; Feliubadaló, J.; Domingo, J. L., Air concentrations of PCDD/Fs, PCBs and PCNs using active and passive air samplers. Chemosphere 2008, 70, (9), 1637-1643. 14. Pozo, K.; Harner, T.; Lee, S. C.; Wania, F.; Muir, D. C.; Jones, K. C., Seasonally resolved concentrations of persistent organic pollutants in the global atmosphere from the first year of the GAPS study. Environmental science & technology 2009, 43, (3), 796-803. 15. Shoeib, M.; Harner, T., Characterization and comparison of three passive air samplers for persistent organic pollutants. Environmental Science & Technology 2002, 36, (19), 4142-4151. 16. Bogdal, C.; Müller, C. E.; Buser, A. M.; Wang, Z.; Scheringer, M.; Gerecke, A. C.; Schmid, P.; Zennegg, M.; MacLeod, M.; Hungerbühler, K., Emissions of Polychlorinated Biphenyls, Polychlorinated Dibenzo-p-dioxins, and Polychlorinated Dibenzofurans during 2010 and 2011 in Zurich, Switzerland. Environmental Science & Technology 2014, 48, (1), 482-490. 17. Li, X.; Li, Y.; Zhang, Q.; Wang, P.; Yang, H.; Jiang, G.; Wei, F., Evaluation of atmospheric sources of PCDD/Fs, PCBs and PBDEs around a steel industrial complex in northeast China using passive air samplers. Chemosphere 2011, 84, (7), 957-963. 18. Bogdal, C. Report on Passive Air Sampling under the Global Monitoring Plan for Persistent Organic Pollutants - GMP Projects 2010-2011 United Nations Environment Programme/DTIE: United Nations Environment Programme/DTIE, 2012. 19. Bogdal, C.; Scheringer, M.; Abad, E.; Abalos, M.; van Bavel, B.; Hagberg, J.; Fiedler, H., Worldwide distribution of persistent organic pollutants in air, including results of air monitoring by passive air sampling in five continents. TrAC Trends in Analytical Chemistry 2013, 46, (0), 150-161. 20. Aristizábal, B. H.; Gonzalez, C. M.; Morales, L.; Abalos, M.; Abad, E., Polychlorinated dibenzo-p-dioxin and dibenzofuran in urban air of an Andean city. Chemosphere 2011, 85, (2), 170-178. 21. Abad, E.; Caixach, J.; Rivera, J.; Gustems, L.; Massagué, G.; Puig, O., Temporal trends of PCDDs/PCDFs in ambient air in Catalonia (Spain). Science of The Total Environment 2004, 334–335, (0), 279-285.

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419 420 421 422 423 424 425 426 427 428 429 430 431 432

Environmental Science & Technology

22. Menichini, E.; Iacovella, N.; Monfredini, F.; Turrio-Baldassarri, L., Atmospheric pollution by PAHs, PCDD/Fs and PCBs simultaneously collected at a regional background site in central Italy and at an urban site in Rome. Chemosphere 2007, 69, (3), 422-434. 23. Katsoyiannis, A.; Gioia, R.; Sweetman, A. J.; Jones, K. C., Continuous Monitoring of PCDD/Fs in the UK Atmosphere: 1991−2008. Environmental Science & Technology 2010, 44, (15), 5735-5740. 24. Brubaker, W. W.; Hites, R. A., Polychlorinated Dibenzo-p-dioxins and Dibenzofurans:  Gas-Phase Hydroxyl Radical Reactions and Related Atmospheric Removal. Environmental Science & Technology 1997, 31, (6), 18051810. 25. Gullett, B. K.; Touati, A., PCDD/F emissions from forest fire simulations. Atmospheric Environment 2003, 37, (6), 803-813.

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Table 1. Information on the 13 sampling sites, average concentrations, minimum and maximum valuesa Site Sonora Yucatan Tapanti Quito Manizales Arauca São Paulo São Luis São Jose dos Ausentes Salta Malargüe Mendoza Rio Gallegos

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Long [º] -109.9 -90.4 -83.9 -78.5 -75.4 -70.8 -46.7 -44.1

Σ4-8PCDD/Fs [fg/m3]

Σ17TEQ PCDD/Fs [fg TEQ/m3]

24.5 25.8 14.1 15.9 13.6 27.3 20.5 27.9

Lat [º] 27.1 20.9 9.8 -0.1 5.1 7.1 -23.6 -2.4

Mean 1311 546 14 213 286 167 1581 1629

Min 893 513 11 208 223 128 1468 701

Max 1608 606 18 218 444 195 1694 2557

Mean 20 7.3