Persistent Organic Pollutants in Austrian Human Breast Milk Collected between 2013 and 2016
, Nadja Haiden 4 and Maria Uhl 1Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
This manuscript reports the results of the human breast milk monitoring study conducted in Austria between 2013-2016. The POPs which were investigated in this study include PCDD/Fs, PBDEs, PFAS, etc.
Suggestions of revisions are provided below.
1. There are no quality control data provided in this manuscript. Please provide, QA/QC (incl. method performance) for all contaminant groups.
2. Line 191: ‘..cleaned tab water..’ – Please correct the spelling of ‘tap’.
3. Line 403: ‘In the follow-up study 2014-2016, 19 of the 25 PFAS analysed were detected in at least one of the 40 human breast milk samples.’ – As can be seen from Table S1, lower LOQs for most of the measured PFAS were achievable for the follow-up study (2014-2016). This can be added here so that it remains clear that one of the reasons for the detection of 19/25 PFAS in the follow-up study was the lower LOQs that were achievable for PFAS in the follow-up study.
4. Table S1: it is not clear if the LOD and LOQ for PFPeS, PFNS, EtFOSAA, 4:2 FTSA, 6:2 FTSA, 8:2 FTSA, DONA, F-53B, and GenX are for pilot study, follow-up study or WHO/UNEP study? Please add the number (1/2/3)
5. Line 421: ‘..in a breast milk sample in Europa..’: Please correct the spelling of ‘Europe’.
6. Line 502: ‘..breast milk surveys in the 502 past were..’: Please replace ‘were’ with ‘where OR wherein’
7. Section 3.3.2: With the updated WHO TEFs now published (DeVito et al., 2023, https://doi.org/10.1016/j.yrtph.2023.105525), it would be relevant if authors could also comment on the impact of new TEFs on the total TEQ in this study.
Comments on the Quality of English Language
The manuscript is well-written, and the content is explanatory.
Author Response
We would like to thank the reviewer for her/his time and review and the valuable comments and suggestions!
Reviewer: This manuscript reports the results of the human breast milk monitoring study conducted in Austria between 2013-2016. The POPs which were investigated in this study include PCDD/Fs, PBDEs, PFAS, etc. Suggestions of revisions are provided below.
- There are no quality control data provided in this manuscript. Please provide, QA/QC (incl. method performance) for all contaminant groups.
Answer: Thank you very much for your comment! More details on QA/QC were provided in the manuscript and in the SI. Primarily, information on recovery rates and used isotopically labelled standards are included. Please see included information in the text of the manuscript, as well as Table S2 in the Supplement.
- Line 191: ‘..cleaned tab water..’ – Please correct the spelling of ‘tap’.
Answer: Typo was corrected, thank you for your notice!
- Line 403: ‘In the follow-up study 2014-2016, 19 of the 25 PFAS analysed were detected in at least one of the 40 human breast milk samples.’ – As can be seen from Table S1, lower LOQs for most of the measured PFAS were achievable for the follow-up study (2014-2016). This can be added here so that it remains clear that one of the reasons for the detection of 19/25 PFAS in the follow-up study was the lower LOQs that were achievable for PFAS in the follow-up study.
Answer: Thank you very much for your valuable comment! We added the following paragraph in the revised manuscript: “The LODs and LOQs of PFAS determined in the follow-up study 2014-2016 are notable lower compared to those of the pilot study 2013 (cf. Table S1 in die SI), which is due to the application of an improved analytical method. This clearly shows why considerably higher detection rates were observed in the follow-up study.”
- Table S1: it is not clear if the LOD and LOQ for PFPeS, PFNS, EtFOSAA, 4:2 FTSA, 6:2 FTSA, 8:2 FTSA, DONA, F-53B, and GenX are for pilot study, follow-up study or WHO/UNEP study? Please add the number (1/2/3)
Answer: LODs/LOQs of the substances mentioned refer to the follow-up study (2), and were only investigated in (2). We are confident that it is transparent to which study the LOQs/LODs belongs, as this information is given in the table on the right side. We would respectfully ask to refrain from providing this information additionally.
- Line 421: ‘..in a breast milk sample in Europa..’: Please correct the spelling of ‘Europe’.
Answer: Typo was corrected.
- Line 502: ‘..breast milk surveys in the 502 past were..’: Please replace ‘were’ with ‘where OR wherein’
Answer: Typo was corrected.
- Section 3.3.2: With the updated WHO TEFs now published (DeVito et al., 2023, https://doi.org/10.1016/j.yrtph.2023.105525), it would be relevant if authors could also comment on the impact of new TEFs on the total TEQ in this study.
Answer: Thank you very much for this input. We calculated the results based on TEF WHO 2022, and reported both the WHO-22 TEQs and the WHO-05 TEQs. Further, DeVito et al., 2023 was included as reference and a statement related to WHO-05 vs. WHO-22 was included.
During the revision of this section, we unfortunately identified an error using the wrong BE value for PCDD/F-PCB results (the value of 15 ng/g for blood was used instead of 0.0002 ng/g for breast milk). This has been corrected and leads to a change in the interpretation of the results. Please consider the changes in the version of the manuscript in correction mode. The section has been rephrased: “Dioxins and furans were detected in a concentration of 0.0032 ng/g fat WHO-PCDD/F-toxic equivalent (TEQ WHO-05) resp. 0.0021 ng/g fat WHO-PCDD/F-toxic equivalent (TEQ WHO-22) in the pooled breast milk sample and were thus below the levels identified in the WHO study 2000-2012 [74], in the WHO study 2007 [70] as well as in other European studies [71]. The detected concentration was also below the mean level for Austria of 0.011 ng/g lipid in the WHO study 1992/93. Polychlorinated biphenyls were detected at a concentration of 0.0023 ng/g lipid WHO-PCB-TEQ (WHO-05) resp. 0.0012 ng/g lipid WHO-PCB-TEQ (WHO-22). The PCDD/F-PCB-TEQ in the present sample was 0.0033 ng/g (WHO-22) being 16.5-times higher than the BE value (PCDD/F-PCB-TEQ) of 0.0002 ng/g fat [74].
The reevaluation of the WHO toxic equivalency factors (TEF) for chlorinated dioxin-like compounds [80] leads to lower TEQs WHO-22 compared to TEQs WHO-05 in the pooled breast milk sample of the present study, which is also shown by data from other international investigations.”
Comments on the Quality of English Language: The manuscript is well-written, and the content is explanatory.
Answer: Thank you very much for your time and your favorable review!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authorsattached file
Comments for author File: Comments.pdf
Author Response
We would like to thank the reviewers for her/his time and review and the valuable comments and suggestions!
The aim of the present study was to investigate the exposure to POPs and some other xenobiotics in breast milk of Austrian mothers collected in 2013-2016. The results of the Austrian data of the WHO/UNEP milk survey from 1987/88 and 1992/93 were compared with the new data. Based on the results obtained, the authors analyzed the health risk of infants consuming their mothers' milk. The research on human milk presented in the study included pilot studies (20 PBDE congeners and 14 PFAS) and actual studies (25 PFAS) in milk collected in 2014-2016. Selected POPs compounds were also analyzed in one collective sample. New scientific evidence on the harmful effects of chemicals, particularly PBDEs and PFAS, show that these chemicals are far more toxic than previously thought. The collected data and research conducted are very important from the point of view of infant health.
The manuscript, in my opinion, is interesting and valuable and brings interesting new insights especially for PFAS compounds in milk. To help improve the manuscript, I would like to ask for clarification on the following points:
The number of samples does not seem to be very large ?
Answer: Thank you for your comment, which is definitely correct. The sample size is not representative for the Austrian population, nevertheless, the study results show - in line with other European and Global Monitoring Plan (GMP) studies - the decrease in POPs exposure demonstrating the effectiveness of the Stockholm Convention. Thus, reporting these study results are important, also to deliver comparable data for other countries and agencies, although investigations in a study population with higher sample size is recommended.
Why were polybrominated diphenyl ethers (PBDEs) not analyzed in studies conducted in 2014-2016?
Answer: Unfortunately, we did not have sufficient funds available.
Please provide the names, company, country of origin of the standards used to determine the tested compounds, as well as the names of the surrogate standards PBDE and PFAS.
Answer: Labelled standards were provided by Wellington Laboratories. This information was added to the manuscript.
Why were POPs compounds determined only in one collective sample? lt is difficult to determine trends on this basis.
Answer: This is correct. Nevertheless, the investigation of POPs in only one pooled breast milk sample per country is foreseen in the WHO/UNEP monitoring programme, where we participated.
Lines 605-607, Line 652 - no literature source
Answer: Thank you for your notice! We checked all references and revised were necessary.
The conclusions chapter should not contain literature citations.
Answer: We revised the conclusion and removed the references in this chapter. Please note, that we now partially shifted information previously stated in the conclusion chapter to other sections of the manuscript (please see the revised manuscript in correction mode).
The citation should be in accordance with the requirements of the publisher. Check the whole manuscript, please. Authors should also carefully check for grammar, punctuation, and sentence structure before submitting the revised paper.
Answer: Thank you very much for this comment. We used the citation software Citavi 6. We imported the references using the Citavi-picker and used the reference style Toxics (MDPI). The reference style and the applied citation should be in accordance with the requirements of the publisher.
A colleague which has studied English (but not a native speaker) checked the entire manuscript related grammar and spelling. Nevertheless, we are not native speakers, unfortunately we are sure that there are still some errors.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors-
Comments on the Quality of English LanguageI have one suggestion on the edited version.
Lines 511-520: What is 'resp.' ? If authors are using 'resp.' as the short form of 'respectively', the two sentences in which 'resp.' is added, needs modification, else, the sentences seems grammatically incorrect.
Perhaps a minor modification like the following in the two sentences would do the needful:
Dioxins and furans were detected at concentrations of 0.0032 ng/g fat (WHO-PCDD/F-toxic equivalent, TEQ WHO-05) and 0.0021 ng/g fat (WHO-PCDD/F-toxic equivalent, TEQ WHO-22) in the pooled breast milk sample.
Polychlorinated biphenyls were detected at concentrations of 0.0023 ng/g lipid (WHO-PCB-TEQ, WHO-05) and 0.0012 ng/g lipid (WHO-PCB-TEQ, WHO-22).
