HSE Health & Safety

Executive

Dioxin exposure from work related activities

Prepared by Lancaster University for the Health and Safety Executive 2002

RESEARCH REPORT 027

HSE Health & Safety

Executive

Dioxin exposure from work related activities

Dr Andy Sweetman, Dr Rob Lee and Prof Kevin Jones

Department of Environmental Science Institute of Environmental and Natural Science

Lancaster University Lancaster

LA1 4YQ United Kingdom

Following concern raised by DEFRA about the potential for occupational exposure to polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo furans (‘dioxins’), Lancaster University were asked by the Health and Safety Executive (HSE) to undertake a sampling and analysis campaign of industrial indoor air. This report covers the findings of a second study and includes static air monitoring and personal air sampling using portable equipment. Both systems used polyurethane foam (PUF) to trap vapour phase contaminants and glass fibre filters for the particulate phase. Industries included in this study were aluminium and copper recycling, waste incineration and landfill operation. Hence, this study was designed to quantify occupational exposure via inhalation for a variety of industries and compare these estimates to dietary intake and the Committee on Toxicity Tolerable Daily Intake values.

This report and the work it describes were funded by the HSE. Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.

HSE BOOKS

© Crown copyright 2002Applications for reproduction should be made in writing to:Copyright Unit, Her Majesty’s Stationery Office,St Clements House, 2-16 Colegate, Norwich NR3 1BQ

First published 2002

ISBN 0 7176 2573 7

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise) without the prior written permission of the copyright owner.

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1. Background

Following concern raised by DEFRA about the potential for occupational exposure to

polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo furans (‘dioxins’), Lancaster

University were asked by the Health and Safety Executive to undertake a sampling and

analysis campaign of industrial indoor air. This report covers the findings of a second study1

and includes static air monitoring and personal air sampling using portable equipment. Both

systems used polyurethane foam (PUF) to trap vapour phase contaminants and glass fibre

filters for the particulate phase. Industries included in this study were aluminium and copper

recycling, waste incineration and landfill operation. Hence, this study was designed to

quantify occupational exposure via inhalation for a variety of industries and compare these

estimates to dietary intake and the Committee on Toxicity Tolerable Daily Intake values.

2. Sample collection and analytical procedure

2.1 Hi-volume samples

Sampling was based on the USEPA method TO4 using General Metal Works high volume air

samplers (model PS-1), calibrated prior to use. Each sample consisted of a glass fibre filter

backed up by two PUF plugs (5cm x 3cm radius). The filters were cleaned by baking at 450ºC

whilst PUF plugs were pre-extracted by soxhlet, first with toluene then DCM. The volume of

air sampled was calculated using the mean flow rate over the sampling period multiplied by

the sampling time. Air samples are typically 500 - 1000 m3 for ambient air measurements but

were typically 100 m3 for this study. Additional information pertaining to the sample, such as

maximum and minimum temperature, relative humidity were also recorded.

2.2 Personal samples.

Sampling was conducted by Health and Safety Laboratories on behalf of HSE and samples

passed on to Lancaster University for analysis. Essentially the personal samplers were based

on the same principle as the Hi-volume samplers - consisting of a glass fibre filter and a PUF

plug (7.6cm x 2.2 cm diameter). Sample preparation procedures were also the same as for the

Hi-volume samplers.

1 Previous study – project number 4176/R51.307

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2.3 Spiking Procedure 13C12 labelled surrogates for all 2,3,7,8-substituted PCDD/Fs were added to each sample prior

to extraction for purposes of quantification and recovery calculation. Immediately prior to

quantitation an injection spike was added to the final extract to act as a retention index for the

GC, and as a recovery standard to allow the calculation of recoveries of all other spiked

compounds. Finally, 37Cl4 labelled 2,3,7,8-TCDD was used as injection spike.

2.4 Transport and Storage

Sample heads were assembled, with pre-cleaned PUF plugs and glass fibre filter, in the

laboratory with each end wrapped in hexane-rinsed aluminium foil. The foil was then

removed immediately prior to sampling and fresh hexane-rinsed foil used to rewrap each end

of the sample head once sampling has finished. Field blanks were treated likewise although

no air was drawn through the sample head.

Sample heads were stored in a cool-box containing freezer blocks for transport to and from

the field site.

Once back in the laboratory the sample heads were dismantled and the filter and PUF plugs

transferred either directly to a soxhlet apparatus or, if the sample required storage before

extraction, to glass jars with aluminium foil lagged lids. These were stored in a freezer at -

20ºC.

A range of solid samples were also collected on site ranging from ambient dust to PFA,

bottom ash and bag plant/scrubber particulates. These samples were stored in pre-cleaned air

tight containers and returned to the laboratory for analysis. Again, they were stored in a

freezer at -20ºC.

2.5 Extraction and Clean-up

Samples were generally analysed in batches of six or twelve, including a field blank and a

reference soil. Extraction was by soxhlet with toluene for 16 hours.

1ml n-nonane was added to the extract as a keeper solvent and the toluene completely

removed under reduced pressure on a rotary evaporator before continuing to the two step

clean-up stage. The extract was cleaned by elution through an adsorption chromatography

column containing acid-modified silica gel, base-modified silica gel and activated neutral

silica gel. The eluate was again concentrated to n-nonane on a rotary evaporator. The extract

in n-nonane was applied to a column of 4.5g alumina which had been pre-rinsed with 30ml n­

hexane. The column was first eluted with 20ml 7% DCM/n-hexane to separate other

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halogenated organic compounds that would otherwise interfere with analysis. The column

was finally eluted with 20ml 1:1 DCM/n-hexane to give a fraction containing and all

PCDD/Fs.

The eluate containaing the PCDD/Fs was reduced to ca 0.5ml at 40ºC under a stream of dry

nitrogen then quantitatively transferred to a tapered 1ml GC vial. 15ml of a solution

containing the injection spike was added and the extract blown down to ca 15ml under the

same conditions. The vial was capped and stored in a fridge at 4ºC until required for analysis

by HRGC-HRMS.

2.6 Quantitation

Quantitation of PCDD/Fs was carried out by HRGC-HRMS using a HP6890 GC fitted with a

HP 6890 series autosampler connected to a Micromass Autospec Ultima high resolution mass

spectrometer run in SIR mode with a resolving power of 10,000.

Each PCDD/F sample was analysed on two different capillary GC columns to allow

quantitation on a total homologue, and on an individual 2,3,7,8-substituted congener basis.

The columns used were 30m DB5-ms (0.25mm i.d., 0.1mm film thickness) and 60m SP2331

(0.25mm i.d., 0.2mm film thickness).

Peak identification was based on retention time as well as ion ratio of the two masses

monitored for each homologue. The quantitation software automatically discounts peaks lying

outside the set acceptance criteria. The integration of every chromatogram was checked

manually before it was accepted.

Quantitation of analytes was made by isotope dilution relative to the internal standard using

the peak areas of the specific 13C12 surrogate for each 2,3,7,8-PCDD/F analyte. Recoveries of

each surrogate were calculated relative to the injection standard.

3. Results

The analytical results from this study are contained in Table 1. Generally, the air

concentrations measured using the static Hi-volume samplers were higher than those

measured using the personal air samplers. Hi-volume air concentrations ranged between 0.06

and 214 pgTEQ m-3 and personal air sample concentrations ranged from 0.16 to 55 pgTEQ m­

3. Another high personal air sample was reported as 59 pgTEQ m-3, the PCDD/F loading of

which was entirely associated with the filter. Hence, this sample might have been

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contaminated during the collection process as the corresponding PUF contained levels below

the detection limits. Although the majority of the PCDD/F burden is generally associated with

particles, the PUF usually contain measurable amounts. It is interesting for comparison that

typical ambient air levels are considerably lower ranging from 1 to 30 fgTEQ m-3 for a semi­

rural site.

If you assume that an average employee weighing 70 kg breathes 10m3 per shift, and absorbs

all that he breathes, then taking the personal samplers alone, the majority of workers were

exposed to levels below the current recommendation of 2 pgTEQ kg body weight-1 day-1

(COT, 20012) . Two samples resulted in exposure levels greater than the current COT

guidelines. However, if the Hi-volume samples are included then the number of samples

exceeding these recommendations increases.

A number of solid samples were also analysed for PCDD/Fs. The results are also contained

within Table 1. Most of the samples analysed were controlled wastes and although the levels

were relatively high (10s ppb) their handling is strictly controlled. However, a number of

ambient dust samples were also taken and some of these also showed levels up to 1 ppb.

As a result, based on this limited dataset there is evidence that some workers may be exposed

to levels of PCDD/Fs in excess of the COT advised tolerable daily intake via inhalation. This

exposure is in addition to their dietary intake. Hence, further investigation into the nature of

these sources within the workplace is recommended.

2 COT. Committee on Toxicity of Chemicals in Food, consumer products and the environment.

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Table 1 – PCDD/F TEQ concentration data for General Metal Works high volume air samples, personal air monitoring and selected solid samples

Volume PUF GFF filter Total Total Date Sample type Sample location collected SWHO-TEQ SWHO-TEQ SWHO-TEQ SWHO-TEQ

m3 pg m-3 pg m-3 pg m-3 pg g-1

Aluminium recycler 1 08/11/2001 Hi. Vol. Rotary furnace 1 (middle) 203 0.3 5.00 5.3 Hi. Vol. Rotary furnace 2 (end) 188 0.16 8.7 8.9 Hi. Vol. Top furnace (sloping hearth) 202 0.18 3.9 4.1 Personal 0.935 3.8 51.0 55.0 Personal 0.855 0.50 7.6 8.1 Personal 0.908 0.50 3.0 3.5 Personal 0.87 0.58 3.7 4.3

Solid Scrubber waste 2100

Solid Bag plant dust 25000

Aluminium recycler 2 14/11/2001 Hi. Vol. Reverb. Furnace 189 0.04 2.0 2.0 Hi. Vol. Rotary Furnace 189 0.11 22.3 22.4 Hi. Vol. End reverb. Furnace 174 0.16 13.7 13.8 Hi. Vol. Swarf Drier/cleaner 196 0.33 15.2 15.6 Personal 0.835 0.55 5.6 6.1 Personal 0.613 0.41 1.4 1.8 Personal 0.63 0.62 2.5 3.1 Personal 0.765 0.52 0.76 1.3 Personal 0.678 0.40 1.50 1.9

Solid Bag plant dust 3100 Solid Slag 15

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Table 1 cont. – PCDD/F TEQ concentration data for General Metal Works high volume air samples, personal air monitoring and selected solid samples

Volume PUF GFF filter Total Total Date Sample type Sample location collected SWHO-TEQ SWHO-TEQ SWHO-TEQ SWHO-TEQ

m3 pg m-3 pg m-3 pg m-3 pg g-1

Municipal Waste Incinerator 28/11/2001 Hi. Vol. Bottom ash collection hall 166 0.04 0.04 0.08

Hi. Vol. Bottom ash transfer (indoors) 158 0.02 0.05 0.06 Hi. Vol. Rubbish Hall 161 0.004 0.34 0.34 Hi. Vol. Tipping Hall 223 0.01 0.061 0.071 Personal 1 0.877 <0.7 0.25 0.25 Personal 2 0.867 <0.8 0.16 0.16

Solid Dust sample 1 7

Solid Dust sample 2 100

Landfill site 19/11/2001 Hi. Vol. Loading Bay 200 0.007 0.12 0.13 Hi. Vol. Platform 202 0.015 0.15 0.16

Personal 1 0.504 0.55 1.10 1.65 Personal 2 0.462 <0.7 59.2** 59.2

Solid AFC inlet 36

Solid Tipper waste 67

Aluminium recycler 3 15/01/2002 Hi. Vol. Rotary furnace - 1 116 0.15 2.7 2.9 Hi. Vol. Rotary furnace - 2 83 0.35 16.0 16.0 Hi. Vol. Mud House 159 0.046 1.4 1.4 Personal 2 0.621 <2.24 <2.3 <4.5 Personal 4 0.531 <2.24 <2.2 <4.5 Personal 5 0.624 <2.24 <2.2 <4.5

Solid Bagplant dust 1 670 Solid Bagplant dust 2 650

* Individual was suspected of tampering with pump. High GFF filter concentration but PUF concentration was less than detection limits.

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Table 1 cont. – PCDD/F TEQ concentration data for General Metal Works high volume air samples, personal air monitoring and selected solid samples

Volume PUF GFF filter Total Total Date Sample type Sample location collected SWHO-TEQ SWHO-TEQ SWHO-TEQ SWHO-TEQ

m3 pg m-3 pg m-3 pg m-3 pg g-1

Aluminium recycler 4 06/02/2002 Hi. Vol. Furnace Front 155 13.6 200 214 Hi. Vol. Furnace Back 102 21.1 45.0 66

Solid Dust 1 1100 Solid Dust 2 1100

Electrostatic precipitator PFA 11/01/2002 Solid U2B5B 0.20

Power Station Solid Boiler bottom ash U2 0.02 Mechanical PFA U2B1

Solid 0.31

Building block IBA 1 10 manufacturer 12/02/2002 Solid

Solid IBA 2 12

Note – Field blanks SWHO-TEQ (PUF and GFF) high volume air samples <0.02 pg m-3 and personal air samples <4 pg m-3

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