Talk:Health effects of Baltic herring and salmon: a benefit-risk assessment
Contents
Submission details
- The manuscript was submitted to BMC Public Health on 4 Dec 2018.
Letter to editor
Sir/Madam,
Please find enclosed our manuscript "Health effects of Baltic herring and salmon: a benefit-risk assessment". Our assessment looked at Baltic herring and salmon consumption in Denmark, Estonia, Finland, and Sweden and produced estimates on both health benefits of nutrients and risks of pollutants.
When the EFSA risk assessment on dioxins was published in November 2018, we updated our assessment with infertility caused by dioxin-induced sperm concentration reduction. This is both timely and important, because EFSA's new assessment sets the tolerable weekly intake for dioxins to one seventh (2 pg/kg/week) of what it was earlier (14 pg/kg/week). This seems to imply that dioxins are much larger problem than previously thought. However, the new risk estimate has to be put in perspective; also EFSA recommended new benefit-risk assessments when it published its new asseessment.
We demonstrate that in a benefit-risk setting, the new risk estimate does not change the main conclusions about Baltic fish, which is the major source of dioxins in the Nordic countries. We also performed a value-of-information analysis, which provides understanding about what issues actually would make a rational decision-maker change their mind. The results are not at all obvious, and therefore our work provides an important piece of research for those who want to understand this complex area.
Data collection on humans
An online survey was performed to adult consumers in Denmark, Estonia, Finland, and Sweden by Taloustutkimus Ltd. We asked about fish eating habits but not about health or other sensitive issues. We did not ask or collect identity information of the respondents, except age, gender, and country, which were used for classification in analyses. The survey did not involve any interventions. Due to these reasons, there was no need for ethical approval according to the THL guidance. The consumer survey data was converted to and published as synthetic data, i.e. data that does not represent any real individuals but that has similar statistical properties as the actual data.
Reviewer comments, first revision
We thank reviewers for their constructive critique. It made us realise some clarification needs in the text, and we made an attempt to improve it. The comments also created some minor changes in the assessment model, so we have rerun the whole model, updated numbers, and redrawn all figures. However, this update caused only minor changes in results and did not alter the conclusions.
Reviewer reports:
Mehwish Hussain, PhD (Reviewer 1): Please Explain the following objections
- All the information given in the manuscript is already published in the URL: I could not find any thing new even texts in the manuscript is taken from the website. The only difference is that the text in the website is well written as a manuscript only. Even the graphs are same as given on the website.
- ----arg2584: . As discussed with the editor earlier, the whole assessment was performed openly online on the Opasnet web-workspace since the beginning, and all data, materials, and code was made available to ensure that potential critics may evaluate the content to the very detail. This is not the same thing as scientific publication, where we write the content into a user-friendly format and discuss the results and conclusions thoroughly. In addition, the journal policy allows the use of pre-publishing repositories, so even a direct copy of a manuscript would have been possible on our repository. Content on Opasnet website is not considered as scientific publishing, and it is not indexed in any article database. --Jouni (talk) 09:54, 25 March 2019 (UTC) (type: truth; paradigms: science: comment)
Atif Kamal (Reviewer 3): Manuscript PUBH-D-18-04482: Health effects of Baltic herring and salmon: a benefit-risk assessment
The study reports the potential health risks from Baltic fish which over time was reduced to half in ten years. The authors further elaborated that the beneficial impact of consuming these fish species on cardiovascular risk outweighed the risks of exposure to the dioxins. The study further showed that the critical population subgroup was young women, who may expose their children to pollutants during pregnancy and breast feeding. Since in this group the health risks were almost equal to the health benefits of fishes consumption. The study seems to provide a good set of information on consuming aquatic food (specific fish species) among Baltic population, however, there are certain aspects of this study that need further explanation which are discussed ahead.
Minor aspects
- Title seems incomplete. The title does not represent the background theme, the risk of consuming contaminated herring and salmon contaminated with dioxins and furans. And therefore needs a revision.
- English: The manuscript is written in good English; however, there are some minor mistake/omissions/grammatical errors that need a little revision. A revisit to English correction may fix the issues. A few are mentioned below
- p-10 line 18 Duration estimatess (i.e. estimates)
- p-14 line 12: in the four study countries (the expression is confusing, please rephrase)
- p-14, lin50: this indicates that the uncertainties about what to with respect to young women is clearly larger than with other subgroups (what to ???, I suggest rephrase the sentence).
- page: 7, line 49: The samples were caught between 2009 and 2010 (what samples?? Fish samples??)
Technical comments
- Study is too descriptive
- The questionnaire is described and results analyzed in detail in another article (Pihlajamäki et al, 2018, forthcoming). Population data for each country for year 2016 was available from Eurostat database.
- The area selection was based on landing statistics, please elaborate,
- Modular Monte Carlo simulation model should be explained in detail
- Around 500 respondents were enrolled in each country, what was the selection criteria??, since sample size should be based on the population density of the studied population, how was a sample size of 500 respondents determined?? For each country.
- ----arg0314: . Specific power calculations were not performed to come up with exactly 500 respondents. Rather, the number was based on our own experience on the sample size needed to get reasonable preciseness to semi-quantitative answers. This does not much depend on the target population size. We used similar sample sizes for each country because we wanted to make comparisons between countries. --Jouni (talk) 14:07, 31 March 2019 (UTC) (type: truth; paradigms: science: comment)
- Data was separated for gender and age (18 - 45 years and > 45 years) groups. What about fishermen population? Those having fishing profession are known to have more intakes of fisheries compared with other segment of population
- more information should be provided on the Fish-size-PCDD/F and dioxin-like PCB concentration for each fish species, and country and the its basis i.e. EU Fish II study
- the methodologies are better be incorporated in current manuscript rather refereeing to other publication, as the paper is already too much descriptive, and it affects the holistic sense of a scientific manuscript
- during the survey, how could respondents consider the fish types, laypeople don't have much knowledge of fishes piece, how could survey analyze consumption of different fish species
- How were the Health risks and benefits of Baltic fish consumption and their cardiovascular benefits were estimated / presumed/ or quantified is not clear
- The following should be added to the abbreviation lists: EFSA TWI
- References: Numbering of references is erroneous please correct accordingly
Reviewer comments, second revision
Tuomisto et al. reported an interesting study attempted to explore the potential risks and benefits associated with Baltic fish consumption in several relevant countries. Although this topic may be of some interest of various sectors, including the public and policymakers, the article is unfortunately quite confusing and has huge room of improvement, despite the fact that it has already been revised based on comments from previous reviewers. Below are several major issues for the authors to consider:
Writing and presentation:
The writing and presentation style is uncommon and difficult to follow. It suggests that the authors are not familiar with English academic writing.
- ----arg1779: . The manuscript was read by a professor of the field, and improvements were made based on his comments. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
There are many occasions where claims are not substantiated by appropriate references (e.g. introduction lines 2-7, 8-10, 12-18).
- ----arg5173: . References were added to Background. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
The tables and figures are difficult to read, with non-standard sizes (even the page layout?) and rather unclear annotation.
- ----arg5173: . All figures are redrawn and resized to increase clarity. Also, the figure and table legends were checked and clarified. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
Often they mixed results, methods and discussion together and information was presented in a logical sequence that I found difficult to follow.
- ----arg9262: . The ordering of text was checked. Also a sentence to clarify the manuscript structure was added to Methods. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
In terms of methods, the description made was unclear in many areas, such as that of the consumption survey (timing of survey, exact number of respondents, response rate, sampling strategy, definition of social status etc.). It is also puzzling to see the authors referring the details of the questionnaire to an unpublished work which we have no access to.
- ----arg7007: . More details about the survey method were added. The other paper is still mentioned but is not needed for understanding. Also, the other paper has been published and is openly available. https://doi.org/10.3390/su11164298 --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
The study involved data from multiple countries and regions of the ocean surrounding these countries. It would be helpful to add a map with proper annotation to help readers who are unfamiliar with the geography to understand the scope of the study.
- ----arg7007: . A map added as Figure 1. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
Scientific question, understanding about health risks and methodology:
The authors attempted to understand the health benefits and risks related to fish consumption, but the methods they adopted, at least to me as an epidemiologist, are far from robust. For example, the exposure-response functions they used (Table 1) was based on scattered studies of varying qualities and robustness, as oppose to more reliable sources such as systematic reviews and meta-analyses.
- ----arg7007: . We updated our literature search and found many new meta-analyses and Cochrane reviews published since the beginning of our project. Based on this, many exposure-response functions were updated or added. We thank the reviewer for this comment, as it improved and updated our manuscript significantly and made both the results and conclusions more robust. (It also caused a lot of work, which delayed the re-submission of our manuscript.) --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
They also inappropriately assumed certain health benefits of fish consumption related to omega-3 fatty acids that are yet to be proven to be causal.
- ----arg7007: . This is extensively discussed in the Discussion section based on new literature that was not available to us when we performed the study. Also, we did not assume causality beyond what the meta-analyses interpreted their own results. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
This indicates that the authors have certain misunderstanding about epidemiology and causal inference, and that the reliability and values of their results of their analyses are quite questionable. This is a fundamental problem that must be resolved.
- ----arg7007: . As mentioned above, the whole analysis is now more tightly based on up-to-date meta-analyses (including Cochrane reviews). The analyses included the possibility that there is no causal connection or that the relation has an opposite sign, as many confidence intervals went beyond zero effect. However, it is important to see that quantitative benefit-risk assessments should contain also effects that are plausible but not certain; this is now discussed in the manuscript. Also, an important method to evaluate the robustness of results is to use value-of-information analysis. We did exactly that and evaluated the importance of all parameter uncertainties. Based on the analysis, our conclusions seem robust. --Jouni (talk) 12:15, 9 May 2019 (UTC) (type: truth; paradigms: science: comment)
Päivi H's comments
1. Tärkein! Huomasin, että acknowledgementeissa ei ollut mainintaa rahoittajasta. Se olisi erittäin tärkeä olla: ----arg2923: . This already was under Funding --Arja (talk) 10:59, 5 February 2019 (UTC) (type: truth; paradigms: science: comment)
This work resulted from the BONUS GOHERR project (Integrated governance of Baltic herring and salmon stocks involving stakeholders) that was supported by BONUS (Art 185), funded jointly by the EU, the Academy of Finland and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning.
3. Muutama kohta oli, jossa dioxin oli yksikössä -> Dioxins
4: yhdestä kohdasta taisi puuttua or -sana: reasons to eat OR to not to eat those ----arg2923: . Fixed --Arja (talk) 10:59, 5 February 2019 (UTC) (type: truth; paradigms: science: comment)
5. Exposures to pollutants and nutrients were simply products of consumption amounts AS ASSESSED BY THE RESPONDENTS OF THE SURVEY and ...(pitäiskö lisätä tuo?) ----arg2923: . Added --Arja (talk) 10:59, 5 February 2019 (UTC) (type: truth; paradigms: science: comment)
6. This indicates that the uncertainties about what to with respect to young women -> PUUTTUUKO TÄSTÄ JOKU SANA? (ABOUT WHAT TO WITH RESPECT TO...)
7. Nyt jos jotain virheitä löytyi Survey-kässäristä, vaikuttaako ne tähän? Onhan nämä kaksi artikkelia nyt koherentit kyselytulosten osalta?
