Annex C - Statement for use of the 2020 EFSA Opinion on the risks to human health related to the presence of perfluoroalkyl substances in food in UK risk assessments

Dust exposures

1.              A literature search was carried out for concentrations of PFAS in dust. There were few UK data. Therefore, data from countries in the EU where dust samples in the home had been collected, were also considered. Only studies with samples collected in homes that had median and/or maximum values were included in the exposure calculations. Tables 1 to 4 show the study information and dust concentrations for PFOS and PFOA, PFHxS and PFNA, respectively.

Table 1. Concentrations of PFOS in dust (ng/g) in UK and EU studies where samples were taken in homes, after 2008.

Values are given to 2 significant figures. SEM – standard error of the mean; LB - lower bound assigns the value of zero to non-quantified data; UB - upper bound assigns the value of the LOD/LOQ to non-quantified data; SD – standard deviation; 95% CI – 95th percent confidence interval; NC not calculated; ND – not determined; LOD – limit of detection; LOQ – limit of quantification; #calculated from individual data in the published paper.

Table 2. Concentrations of PFOA in dust (ng/g) in UK and EU studies where samples were taken in homes, after 2008.

Values are given to 2 significant figures. SEM – standard error of the mean; LB - lower bound assigns the value of zero to non-quantified data; UB - upper bound assigns the value of the LOD/LOQ to non-quantified data; SD – standard deviation; 95% CI – 95th percent confidence interval; NC not calculated; LOD – limit of detection; LOQ – limit of quantification; #calculated from individual data in the published paper.

Table 3. Concentrations of PFHxS in dust (ng/g) in UK and EU studies where samples were taken in homes, after 2008.

Values are given to 2 significant figures. SEM – standard error of the mean; LB - lower bound assigns the value of zero to non-quantified data; UB - upper bound assigns the value of the LOD/LOQ to non-quantified data; SD – standard deviation; 95% CI – 95th percent confidence interval; NC not calculated; ND – not determined; LOD – limit of detection; LOQ – limit of quantification; #calculated from individual data in the published paper.

Table 4. Concentrations of PFNA in dust (ng/g) in UK and EU studies where samples were taken in homes, after 2008.

Values are given to 2 significant figures. SEM – standard error of the mean; LB - lower bound assigns the value of zero to non-quantified data; UB - upper bound assigns the value of the LOD/LOQ to non-quantified data; SD – standard deviation; 95% CI – 95th percent confidence interval; NC not calculated; ND – not determined; LOD – limit of detection; LOQ – limit of quantification; #calculated from individual data in the published paper.

2.                 The exposure estimates are based on concentrations derived as an average of the median (Table 5) or maximum (Table 6) values reported in the literature.

Table 5. Concentrations derived (ng/g) as an average of the median values reported in the literature.

Concentrations are given to 2 sig. figs.

Table 6. Concentrations derived as an average of the maximum values reported in the literature.

Concentrations are given to 2 sig. figs.

3.                 Dust ingestion rates were taken from the EPA Exposure Factors Handbook (2011) Exposure Factors Handbook 2011 Edition (Final Report) | Science Inventory | US EPA which had been updated in 2017. Average bodyweights for the UK populations were calculated from NDNS (18 months – 95 years) and DNSIYC (4 – 18 months) data for different age groups. These are all shown in Table 7. Two bodyweights were provided for the toddler age group: 10 Kg for the 7 - 18 months age group and 16 Kg for those aged 18 months to 4 years. As the 16 Kg represented a wider age range, that was used in the exposure calculations.

4.                 Exposures from dust ingestion were calculated for median and high concentrations of PFOS, PFOA, PFHxS and PFNA and mean median ingestion rates, for each UK population group (Table 8).

Table 7. Dust ingestion rates and average UK bodyweights for UK population groups.

5.                 For the average median PFASs concentrations in dust, the following ranges of exposures were calculated for all UK population groups for each of the compounds (Table 8):

• PFOS (59 ng/g): 0.014 – 1.9 ng/kg bw per week
• PFOA (66 ng/g): 0.015 – 2.1 ng/kg bw per week
• PFHxS (55 ng/g): 0.013 – 1.8 ng/kg bw per week
• PFNA (0.22 ng/g): 0.000051 – 0.0071 ng/kg bw per week

6.                 For the average maximum PFASs concentrations in dust, the following ranges of exposures were calculated for all UK population groups for each of the compounds (Table 8):

• PFOS (1300 ng/g): 0.30 - 42 ng/kg bw per week
• PFOA (660 ng/g): 0.15 – 21 ng/kg bw per week
• PFHxS (910 ng/g): 0.21 – 29 ng/kg bw per week
• PFNA (14 ng/g): 0.0032 – 0.45 ng/kg bw per week

7.                 For all PFASs considered, infants had the highest exposures and teenagers, adults and seniors had the lowest exposures.

Table 8. Estimated exposures for PFOS, PFOA, PFHxS and PFNA (ng/kg bw per week) for UK population groups (mean dust ingestion rates (mg/day).

Mean dust ingestion rates: infants 36 mg/day; toddlers 41 mg/day; children 32 mg/day; teenagers 2.2 mg/day; adults and seniors 2.6 mg/day.

COT
October 2022
Statement Number 04/22

References

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