Response to academic editor and reviewer(s)
Respected Academic Editor and Reviewers,
Thank you so much for your comments. We are very grateful to you for the time and
intelligence that you have shared with us. It is a great learning opportunity for
us through these reviews. Our responses to the comments are highlighted in red color
in the revised manuscript.
Comments and Suggestions for Authors:
Response to the Recent Comments of the Academic Editor
Academic editor comment (17-02-23): Thank you for your responses. Please update your
Figure Captions in Figure 1 to include attribution to ESRI. Once this is done, we
should be able to proceed.
Response: We are grateful to the editor for indicating this issue. The caption of
Figure 1 including the attribution to ESRI has been updated as suggested. The revised
caption of Figure 1 is as follows: (Page No. 5, Line No. 142-148)
Fig 1. (a) The study area map showing the sampling location of river water (RW) and
tap water (TW). The map has been produced using ArcGIS 10.4.1 software. The sources
of basemaps of administrative boundaries and inland water bodies: Esri, GADM, Garmin,
DigitalGlobe, GeoEye, GEBCO, USGS, NOAA, National Geographic, EPA, Geonames.org, the GIS User Community and other contributors. (b) The geology of the study area
(the sources of basemaps are similar to (a) and the geological units modified after
[16], [28], [29]).
Academic editor comment 1 (09-02-23): Please amend the title either on the online
submission form or in your so that they are identical.
Response: We thank the editor for this comment. We have changed the title on the online
submission form.
Academic editor comment 2 (09-02-23): Your ethics statement should only appear in
the Methods section of your manuscript. If your ethics statement is written in any
section besides the Methods, please move it to the Methods section and delete it from
any other section. Please ensure that your ethics statement is included in your manuscript,
as the ethics statement entered into the online submission form will not be published
alongside your manuscript.
Response: We appreciate the editor’s feedback. We have added the ethics statement
in the method section and deleted in from any other section as per the editor’s instruction.
Academic editor comment 3 (09-02-23): Regarding the potential copyright of figure
1, please respond to the following prompts:
A. For the above figure, were any shapefiles or basemaps obtained? If so, where were
they obtained? Please provide any relevant links as well as any relevant copyright
information.
B. For the above figure, were any external data utilized in the creation of this figure?
If so, where were they obtained? Please inform us if the data was collected or produced
by the authors. Please also provide any relevant links as well as any relevant copyright
information.
C. Was any software (e.g. ArcGIS) used in the creation of these figures?
Response: We thank the editor for the opportunity to clarify this issue.
A. For figure 1(a), shape files of Bangladesh, administrative boundaries, upazilla
boundary and river shapefiles were obtained from the following links which are free
for educational and research purposes and anyone can access. Shapefile download links
https://www.diva-gis.org/Data
http://maps.barcapps.gov.bd/
B. For creation of the figure 1(a), coordinates of sample collection points obtained
using GPS were used which were collected by the authors during sample collection.
For creation of figure 1(b), authors used the information from the Khan et al., 2020,
Karim et al., 2019, Ahmed et al., 2010 and created a new geological map of Dhaka city
and its periphery regions using CorelDraw X7 graphics software. So far our knowledge,
no copyright issues involved.
C. For creation of figure 1(a), ArcGIS 10.4.1 software was used and for figure 1(b),
CorelDraw X7 graphics software was used.
Previous Comments
Academic Editor
Academic editor comment 1: Please ensure that your manuscript meets PLOS ONE’s style
requirements, including those for file naming. The PLOS ONE style templates can be
found at
https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf
Response: Thank you so much for your kind comments and appreciation of our study.
All of your comments are carefully evaluated and revised in our revision accordingly.
The revised manuscript has been prepared according to Plos One style.
Academic editor comment 2: In your Methods section, please provide additional information
regarding the permits you obtained for the work. Please ensure you have included the
full name of the authority that approved the field site access and, if no permits
were required, a brief statement explaining why.
Response: We thank the editor for this comment. There were no permits required for
doing this work. We collected water samples from the Buriganga river and the tap water
of Dhaka city. The river is wide open and accessible for public usage. Therefore,
no permission was needed to collect the water from the river. On the other hand, we
collected tap water from the houses of friends and relatives, and their verbal permission/consent
were granted before the sampling.
Academic editor comment 3: In your Data Availability statement, you have not specified
where the minimal data set underlying the results described in your manuscript can
be found…
Response: We appreciate the editor’s feedback. All relevant data are available within
the manuscript.
Academic editor comment 4: We note that Figure 1 in your submission contain map images
which may be copyrighted. All PLOS content is published under the Creative Commons
Attribution License (CC BY 4.0), which means that…
Response: We appreciate the editor’s feedback. Figure 1 has been modified in the revised
manuscript, so there will be no copyright issue. Proper citation is given in the figure
title like “
Fig 1. (a) The study area map showing the sampling location of river water (RW) and
tap water (TW). The map has been produced using ArcGIS 10.4.1 software. The sources
of basemaps of administrative boundaries and inland water bodies: Esri, GADM, Garmin,
DigitalGlobe, GeoEye, GEBCO, USGS, NOAA, National Geographic, EPA, Geonames.org, the GIS User Community and other contributors. (b) The geology of the study area
(the sources of basemaps are similar to (a) and the geological units modified after
[16], [28], [29]).” (Page No. 5, Line No. 142-148)
Reviewer #1 comment:
Reviewer 1, comment 1: Author should be changed the title appropriate. “Pioneer” is
exaggerated, “Silent Killer” is not a scientific term.
Response: We thank the reviewer for this valuable comment. We removed the terms “Pioneer”
and “Silent Killer” from the title of the revised manuscript. (Page No. 1, Line No.
1-2)
Reviewer 1, comment 2: Please describe the uncertainty and detection limit of radioactivity
measurement of water sample.
Response: We thank the reviewer for the opportunity to clarify this issue.
We added the following line about uncertainty in the revised manuscript (Page No.
8, Line No. 211-213): “For a cycle when no counts were collected, the RAD7 displays
an uncertainty value based on a two-sigma, 95% confidence interval that is equivalent
to ± 4 counts (Opondo & Sims, 2012).”
The following line about detection limit is added in the revised manuscript (Page
No. 7, Line No. 195-197): “The RAD H2O is an accessory of the RAD7 detector that allows
measuring radon in water at concentrations above the minimum detectable activity (MDA).
The MDA concentration of this instrument is 0.004 Bq/L (Hasan et al., 1999; Kareem
et al., 2020).”
Reviewer 1, comment 3: Please describe the calibration methods and the results for
determination of Rn-222 using RAD7. These leads to reliability of results.
Response: We thank the reviewer for this opportunity to clarify this issue. We calculate
calibration factors by comparing them to “master” RAD7s, which have been compared
to EPA and DOE instruments and have taken part in worldwide radon instrument inter-comparisons.
Our standard RAD7 calibration achieves a repeatability of greater than 2% on average.
The overall calibration precision is within 5%.
Reviewer 1, comment 4: 3.3 Radon in tap water; Last paragraph, authors described that
“a radon mitigation treatment plant should be introduced.” Even though the water and
the associated effective dose were below the USEPA and the WHO limit. Why does it
need? And also described “The water should be aerated and boiled”. Is it necessary
from a dose optimization for point of view?
Response: We thank the reviewer for this comment. We deleted the lines “a radon mitigation
treatment plant should be introduced” and “The water should be aerated and boiled”
from the section 3.3 Radon in tap water; last paragraph of the revised manuscript.
Reviewer #2 comment:
Title: should be modified following the points:
Reviewer 2, comment 1: ‘radon, silent killer in Dhaka city’; based on the findings
of this research work, radon has no potential risks for Dhaka city water. Thus, the
issue about the silent killer in the title should be modified. In addition, this wording
might be alarming for the public or government.
Response: We thank the reviewer for this valuable comment. We removed the term “Silent
Killer” from the title of the revised manuscript. (Page No. 1, Line No. 1-2)
Reviewer 2, comment 2: pioneering study: there are already published articles for
radon in tap water in Dhaka city
For example, (http://article.scholarena.com/A-Study-of-Radon-Concentration-in-Tap-Water-of-Dhaka-City-Bangladesh.pdf), therefore, the clarifying pioneering study should be reconsidered.
Response: We thank the reviewer for this valuable comment. We removed the term “Pioneer”
from the title of the revised manuscript. (Page No. 1, Line No. 1-2)
In the above-mentioned study (http://article.scholarena.com/A-Study-of-Radon-Concentration-in-Tap-Water-of-Dhaka-City-Bangladesh.pdf), the temperature and the humidity did not remain within the limit during analyzing
the radon concentration in water. That is why, the result obtained from that study
may be considered incomplete or all affecting parameters were not presented properly.
We conducted the experiment taking all the precautions to obtain an accurate result.
Abstract:
Reviewer 2, comment 3: authors clarified ‘this study poses a great significance for
the radiological safety of public health’; however, the authors did not indicate any
potential radiological risks/reasons for assessment of radon in river water at Dhaka
city as background. It would be better if the authors clarified a few radiological
exposures pathways/reasons- why radon in river water in Dhaka city is important shortly
in the abstract.
Response: We thank the reviewer for this valuable comment. We removed the line ‘this
study poses a great significance for the radiological safety of public health’ from
the abstract of the revised manuscript.
Reviewer 2, comment 4: ‘RAD H2O detector’; is not a detector, it is an accessory of
RAD7.
Response: We thank the reviewer for indicating this issue. We changed the ‘RAD H2O
detector’ to ‘RAD H2O accessory’ in the revised manuscript. (Page No. 1, Line No.
22-23)
Reviewer 2, comment 5: about the concentration of 1.537 ± 0.380 Bq/L and 0.675 ± 0.285Bq/L;
what is the effective digit to be considered about the values? Why are three digits
selected? It would be better to choose a logical concentration value throughout the
paper.
Response: We thank the reviewer for this valuable comment. We changed the effective
digit to two instead of three in the revised manuscript.
Reviewer 2, comment 6: what is MCL? Nothing is clarified in the abstract.
Response: We thank the reviewer for this valuable comment. We added the
term ‘the maximum contamination limit (MCL) or maximum contaminant level (MCL)’ in
the revised manuscript. (Page No. 1, Line No. 25)
Reviewer 2, comment 7: It would be better if the authors clarify the reason-why it
is important to set a national safety limit for radon in Bangladesh. There is no potential
risk in Bangladesh according to this article.
Response: We thank the reviewer for this valuable comment. We deleted the statement
‘contribute to developing the national safety limit for radon in water in Bangladesh’
in the revised manuscript.
Introduction:
Reviewer 2, comment 8: overall, the description of radon, its limits, characterization
etc., has been mentioned much more than the information regarding the importance/background
of radon study in water in Dhaka.
Response: We thank the reviewer for this valuable comment. In addition to the mentioned
info, we also included the importance/background of radon study in water in Dhaka
city at the later part of the Introduction, which is given as follows for your easy
tracking (Page No. 3, Line No. 74-84).
‘Numerous studies have been performed worldwide to measure the 222Rn level in various
water resources such as tap water, river water, deep well water, bore well water,
bottled water, etc.(Faweya et al., 2021; Mustapha et al., 2002; Rani et al., 2021;
Thumvijit et al., 2020; Yong et al., 2021). Several advanced countries have the national
reference limit of radon in water and indoor air to ensure radiological safety for
public health. Bangladesh has no such reference level for 222Rn in water. Millions
of people living in the Dhaka megacity solely rely on tap water for their daily household
purposes, such as washing, bathing, drinking, cooking, etc. The Buriganga river serves
as one of the busiest major transportation routes/hubs, as well as many businesses
and trade centers that are situated on the bank of this river. This indicates a greater
possibility of 222Rn exposure to the general populace. So, it is necessary to measure
the 222Rn level in the tap water and the Buriganga river water to find out if it is
within the safe limit or not, which eventually will help to ensure the radiological
safety of public health.’
Reviewer 2, comment 9: ‘emanates from the water’; radon emanation is a suitable word
for soil/materials having grain as of radon generation process. For using it on water,
it should be rechecked.
Response: We thank the reviewer for this comment. We changed the term ‘emanates’ to
‘escapes’ in the revised manuscript. (Page No. 2, Line No. 47)
Reviewer 2, comment 10: ‘safe water is essential for human lives, it is a matter of
great concern to evaluate the radon level in the water’; as of the water quality/safety;
radon might not a direct contaminant (following EPA) https://www.epa.gov/dwreginfo/drinking-water-regulations
https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations#Radionuclides
https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=30006644.txt
Response: We thank the reviewer for this valuable comment. We deleted the statement
‘safe water is essential for human lives; it is a matter of great concern to evaluate
the radon level in the water’ in the revised manuscript.
Reviewer 2, comment 11: It is better to use either 222Rn or radon; one form throughout
the texts.
Response: We are grateful to the reviewer for this comment. We changed ‘radon’ into
‘222Rn’ throughout the texts of the revised manuscript.
Reviewer 2, comment 12: ‘Almost every developed country has its national reference
limit of radon in water’; this information should be checked; please insert reliable
references to insert this information.
Response: We are thankful to the reviewer for indicating this issue. We changed
the statement ‘Several advanced countries have the national reference limit of radon
in water and indoor air to ensure radiological safety for public health’ in the revised
manuscript. (Page No. 3, Line No. 76-77)
Reviewer 2, comment 13: The authors clarified, ‘’no studies on radon measurement in
surface water, tap water, or indoor air’’; there are many published articles dealing
with radon in Bangladesh-
https://doi.org/10.1093/oxfordjournals.rpd.a082065
https://doi.org/10.1016/0969-8078(93)90079-J
https://doi.org/10.1016/j.radmeas.2008.03.050
https://doi.org/10.1016/1359-0189(91)90029-H
https://doi.org/10.1016/1359-0189(88)90200-2
https://link.springer.com/article/10.1007/s10661-019-7650-6
http://article.scholarena.com/A-Study-of-Radon-Concentration-in-Tap-Water-of-Dhaka-City-Bangladesh.pdf
It is recommended to look at the papers and insert associated references to understand
the importance of radon research in Bangladesh/Dhaka city.
Response: We are thankful to the reviewer for indicating this issue. We deleted the
statement ‘no studies on radon measurement in surface water, tap water, or indoor
air’ in the revised manuscript.
Reviewer 2, comment 14: Buriganga refers to 20% of the total water demand of Dhaka
city dwellers; please insert a suitable reference here.
Response: We thank the reviewer for this valuable comment. We deleted the statement
‘Nevertheless, it meets around 20% of the total water demand of Dhaka city dwellers’
in the revised manuscript.
Methodology:
Reviewer 2, comment 15: extensive discussion about the Geology of Dhaka city was nicely
given. However, sufficient information is not mentioned in the methodology or results
section about the potential radiological risks, relationship with radionuclide distribution,
or radon exposure following Geology. Please insert some points on radiological risks
based on the Geology.
Response: We thank the reviewer for indicating this issue. In the revised manuscripts,
we added the following section (Page No. 6-7, Line No. 152-174) “2.3 Radiological
risks based on geology: Radon emanates from soils, rocks, alluvial sediments and/or
aquifer matrix and enters the groundwater and air. Radon, the main contributor to
natural background exposure, and its progeny such as 218Po, 214Po, and 214Bi releases
energy after inhalation and/or ingestion causing lining in the stomach and lung cancer
in human body. Therefore, considering the health effect of radon, it is important
to identify the areas with high radon concentration, their source and relation with
local geology to prevent the adverse effects on the human beings and environment (Mostečak
et al., 2018). Though radon occurs naturally in most of the soils, sediments and rocks
as radioactive decay product of 238U but the amount differ in localities and the geological
materials. Radon potential depends on the concentration of naturally occurring radionuclides
such as 238U or 226Ra and 232Th in the soils and types of bedrocks present in the
area (M. A. Khan et al., 2022). Different geological factors such as lithology/rock
type, porosity, permeability, compaction, emanation capacity of ground, soil constituents
and tectonic features like faults, thrust, and joints, along with the geochemical
and hydrogeological conditions of the area mainly control the source, distribution,
transport and migration of radon in the soils, sediments and rocks (Alonso et al.,
2019; Choubey et al., 1997; Majumder et al., 2021). Certain rock types such as granites,
metamorphosed granitic rocks, phosphatic rocks with uranium enrichment, coal deposits,
black shale fractured/faulted rocks and the subsequent soils resulted from these rocks
are the most common sources of radon gas (Appleton & Miles, 2010; M. A. Khan et al.,
2022; Majumder et al., 2021). On the other hand, quartzose sandstone, non-organic
shales and siltstones are least likely source of radon (Gundersen, 1991) but under
favourable reducing environment, uranium mineralization may occur in alluvial type
sedimentary deposits which can then contain and emanate radon (Majumder et al., 2021).
Based on the above facts and the geology of the study area, the radon potential and
their associated health risks are evaluated in this study.”
Reviewer 2, comment 16: sample collection through plastic bottle: please specify what
criteria were filled up collecting water samples to avoid escaping radon. What type
of plastic bottle was used, and what arrangements were taken for the bottle cap? It
is recommended to use glass bottles; it is relatively easier to escape radon from
different plastic bottles. IAEA materials explained such precautions for collecting
water-https://www.iaea.org/sites/default/files/19/11/radon-presentation-bochicchio.pdf
Response: We thank the reviewer for indicating this issue. The bottle was fully submerged
in the water during collecting the samples. After filling, the bottle was sealed instantly
under the water without any water bubbles. The laboratory standard plastic bottles
were used. The caps of the bottles were flexible and sealed tightly. We agree with
the reviewer that it is recommended to use glass bottles; it is relatively easier
to escape radon from different plastic bottles. We had only five glass bottles of
RAD H2O accessories that were used to measure the radon concentration.
Reviewer 2, comment 17: please specify your assessed lower detection limit of RAD7
in measuring water in the research, as the results exhibit lower values.
Response: We thank the reviewer for this valuable comment. The following line is added
in the revised manuscript (Page No. 7, Line No. 195-197): “The RAD H2O is an accessory
of the RAD7 detector that allows measuring radon in water at concentrations above
the minimum detectable activity (MDA). The MDA concentration of this instrument is
0.004 Bq/L (Hasan et al., 1999; Kareem et al., 2020).”
Reviewer 2, comment 18: dosimetry calculation: why CW=730 L/day is used? Thumvijit
et al., 2020 specified 2L/day.
Response: We thank the reviewer for this comment. We corrected the value of CW (Daily
water consumption) = 3 L/day (Rani et al., 2021; WHO, 2017) in the revised manuscript.
(Page No. 9, Line No. 231)
Results and Discussion:
Reviewer 2, comment 19: why is the effective dose for radon (both river and tap water)
achieved from ingestion and inhalation exhibited around similar levels? Studies from
other countries (cited in this article) possess much differences between the two doses.
It would be very interesting if the authors interpret the reasons.
Response: We thank the reviewer for indicating this issue. We have corrected the dose
calculation in the revised manuscript. We used Eq 1 and 2 for calculating ingestion
and inhalation doses, respectively. In Eq. 1, we used EDC (Effective Dose Coefficient)
= 3.5 nSv/Bq for 222Rn ingestion (UNSCEAR, 2010), CW (daily water consumption) =
3 L/day (Rani et al., 2021; WHO, 2017), but in other studies, they used different
values for EDC and CW for calculating ingestion doses. For calculating inhalation
doses by using Eq 2, we used DCF (dose conversion factor for 222Rn exposure) = 9 nSv(hBqm-3)-1
(UNSCEAR, 2010). But different values of DCF were used in other papers. We found different
ingestion and inhalation doses using the values mentioned earlier.
Reviewer 2, comment 20: please specify how this study is consistent with studies from
other countries.
Response: We thank the reviewer for allowing us to explain this matter. According
to the Table 3, this study showed similar results of radon concentration in the Buriganga
river water (0.68 ± 0.29 Bq/L) with Karnataka, India (0.16 - 1.79 Bq/L) (Rajashekara
et al., 2007), Hemavathi River India (0.67 Bq/L) (Shivanandappa & Yerol, 2018), Kirkuk,
Iraq (0.359Bq/L ) (Kareem et al., 2020). The line has been modified in the revised
manuscript like this this (Page No. 12, Line No. 286-289), “Additionally, the result
of this study is consistent with the previous research carried out in different regions
of the world, such as in Karnataka, India (0.16 - 1.79 Bq/L) (Rajashekara et al.,
2007), Hemavathi River India (0.67 Bq/L) (Shivanandappa & Yerol, 2018), Kirkuk, Iraq
(0.359Bq/L ) (Kareem et al., 2020).”
Reviewer 2, comment 21: why ‘a radon mitigation treatment plant should be introduced’
with no elevated radon levels?
Response: We thank the reviewer for this comment. We deleted the lines “a radon mitigation
treatment plant should be introduced” in the revised manuscript.
Reference:
Reviewer 2, comment 22: It is necessary to verify all the references cited in the
text and the reference list needs to be standardized->
Response: We thank the reviewer for this comment. All the references cited in the
text and the reference list are revised and modified accordingly in the revised manuscript.
Reviewer 2, comment 23: authors names were written two times in one reference. Moreover,
authors names could not be found in the website (see reference Ahmed, K. M., & Burgess,
W. G. (2003)).
Response: We are very sorry for these silly mistakes and revised them accordingly.
Reviewer 2, comment 24: same reference was written as a and b. (Al Zabadi, H., Musmar,
S., Issa, S., Dwaikat, N., & Saffarini, G. (2012a). It should be one reference.
Response: We are very sorry for these silly mistakes and revised them accordingly.
Reviewer 2, comment 25: reference could not be found on the journal website with the
correct content. In cited Journal of Chemical Information and Modeling (Vol. 53, Issue
9), nothing is mentioned about the Bangladeshi population on the website.
Response: We are very sorry for these silly mistakes. We corrected the citation in
the revised manuscript.
Reviewer 2, comment 26: incorrect formatting (n.d) was frequently used: Buriganga
Riverkeeper : » History. (n.d.)
Response: We are very sorry for these silly mistakes. We corrected the citation in
the revised manuscript.
Reviewer 2, comment 27: missing title; only journal name and author name were included
(Copes, R., & Peterson, E. (2014). Indoor Radon a Public Health Perspective).
Response: We thank the reviewer for this valuable comment. We modified the reference
in the revised manuscript.
Reviewer 2, comment 28: please check if it is scientifically ok with some references
as suitable for scientific journals (i.e., Banglapedia).
Response: We thank the reviewer for this valuable comment. Banglapedia is a national
encyclopedia which is a reliable source of information and suitable for scientific
journals.
Reviewer 2, comment 29: ResearchGate should not be a reference source for journal
articles to be cited.
Response: We thank the reviewer for indicating this issue. We deleted the ResearchGate
citation a reference source for journal articles in the revised manuscript.
Reviewer 2, comment 30: English language: the overall English language should be improved.
There are problems with wording and grammar.
Response: We thank the reviewer for this comment. The whole manuscript was checked
with thoroughly. We improved the wording and grammar throughout the revised manuscript.
Comments on scientific content:
Reviewer 2, comment 31: scientific problem-oriented background has not been described
in the text especially in the introduction part? What are the scientific purposes
to be newly understood in this work?
Response: We thank the reviewer for this valuable comment. In addition to sources
and effects of radon, we also included the importance/background of radon study in
water in Dhaka city at the later part of the Introduction, which is given as follows
for your easy tracking.
‘Numerous studies have been performed worldwide to measure the 222Rn level in various
water resources such as tap water, river water, deep well water, bore well water,
bottled water, etc.(Faweya et al., 2021; Mustapha et al., 2002; Rani et al., 2021;
Thumvijit et al., 2020; Yong et al., 2021). Several advanced countries have the national
reference limit of radon in water and indoor air to ensure radiological safety for
public health. Bangladesh has no such reference level for 222Rn in water. Millions
of people living in the Dhaka megacity solely rely on tap water for their daily household
purposes, such as washing, bathing, drinking, cooking, etc. The Buriganga river serves
as one of the busiest major transportation routes/hubs, as well as many businesses
and trade centers that are situated on the bank of this river. This indicates a greater
possibility of 222Rn exposure to the general populace. So, it is necessary to measure
the 222Rn level in the tap water and the Buriganga river water to find out if it is
within the safe limit or not, which eventually will help to ensure the radiological
safety of public health.’
Reviewer 2, comment 32: as for the first time obtained data, it is important to ascertain
the radon level in water in Dhaka city river. However, it would be better to make
some statistical analysis to determine how the obtained data from two sources or sample
collection points are significant and associated with each other.
Response: Thank you for your valuable comment. Instead of doing a separate statistical
analysis to obtain the correlation between the sources, we simply reported the mean,
range, standard deviation of the measured values, and we assume that this is an acceptable
approach for the present results. This is because, both sources show a low range of
values (overall, the data of river water is relatively lower than the data of tap
water, which is obvious because of aeration issue of river water).
Reviewer 2, comment 33: how to choose sampling areas/positions/sampling numbers? How
to decide the river and tap water in this study for dose calculation?
Response: We thank the reviewer for indicating this issue. The sampling strategy followed
the stratified sampling technique approved by IAEA (International Atomic Energy Agency,
2019). The purpose of choosing the sampling areas is to evaluate the impact of radon
in high-density populated areas and/or areas of various activities such as boat terminals,
Ghats, business and trade centers etc. for the Buriganga river. As for the tap water
sampling, we wanted to cover Dhaka city where the majority of the people inhabit.
That is why we collected 20 samples from the twenty most impactful areas of the river
and 10 samples from different localities of Dhaka city.
We primarily focused on measuring the radon concentration in polluted water in Dhaka
city. The Buriganga river water was highly polluted and the tap water also contained
pollutants according to recent studies. For this reason, we conducted this study to
measure the radon concentration in the river and tap water
Reviewer 2, comment 34: In conclusion part, considering this work’s purpose, it is
important to insert the new findings and recommendations for future research as an
original research articles (as this is one of the preliminary studies for radon in
water).
Response: We thank the reviewer for indicating this issue. We added the following
lines in the revised manuscript (Page No. 15, Line No. 354-361):
“A few recommendations are proposed for future 222Rn-related works,
• The 222Rn concentration in the other major rivers and the tap water of the other
major cities in the country needs be analyzed for mapping the scenario of radon.
• A detailed work is necessary to measure the 222Rn concentrations in deep-well water,
bottled water, and surface water throughout the country.
• Measurement of 222Rn in air and soil-gas at the different location of the country
is essential to monitor the radon situation.”
Reviewer #2, comment PDF file:
Comment Response Page No., Line No.
The title might need to be modified because of few reasons below-
Based on the findings, radon is not a potential silent killer for Dhaka city due radon
exposures from water. We removed the term “Silent Killer” from the title of the revised
manuscript.
Pioneering study: There is already published results for radon in tap water in Dhaka
city,
http://article.scholarena.com/A-Study-of-Radon-Concentration-in-Tap-Water-of-Dhaka-City-Bangladesh.pdf
--> The title with “silent killer” is seemed to be alarming for public/government
although there is not a potential gas with human exposure for Dhaka
We removed the term “Pioneering” from the title of the revised manuscript.
The purpose of assessing radon in Buriganga river is not clear; based on the information
concerning air radon level in Bangladesh/Dhaka city/ source of radon (elevated radionuclide
in river sediment/groundwater) in Dhaka city has not been clarified.
OR radon as a tool to understand the natural radiation exposure from river? co-existing
pollutant with chemicals in river?
Respected reviewer, in the abstract we mentioned as follows ‘Radon (222Rn), an inert
gas, is considered a silent killer due to its carcinogenic characteristics. Dhaka
city is situated on the banks of the Buriganga River, which is considered the lifeline
of Dhaka city because it serves as a major source of the city's water supply for domestic
and industrial purposes.’.
Also, in the introduction we mentioned as follows ‘Numerous studies have been performed
worldwide to measure the 222Rn level in various water resources such as tap water,
river water, deep well water, bore well water, bottled water, etc.(Faweya et al.,
2021; Mustapha et al., 2002; Rani et al., 2021; Thumvijit et al., 2020; Yong et al.,
2021). Bangladesh has no such reference level for 222Rn in water. Millions of people
living in the Dhaka megacity solely rely on tap water for their daily household purposes,
such as washing, bathing, drinking, cooking, etc. The Buriganga river serves as one
of the busiest major transportation routes/hubs, as well as many businesses and trade
centers that are situated on the bank of this river. This indicates a greater possibility
of 222Rn exposure to the general populace. So, it is necessary to measure the 222Rn
level in the tap water and the Buriganga river water to find out if it is within the
safe limit or not, which eventually will help to ensure the radiological safety of
public health.’
There is existing data for tap water of radon in Bangladesh. Line deleted
It is unclear, what are the potential radiological risks/reasons of radon in river
water at Dhaka city, it is better if the authors clarified few radiological exposure
pathways/reasons-why radon in river water in Dhaka city is important Respected reviewer,
it has been mentioned in the abstract as well as in the later part of introduction.
Also, the same response to your comment no. 3
1) How to select the sampling numbers
2) Relationship between water collected from RIVER and TAP water? Sampling number
was chosen based on the various activities at the river side, while the tap water
sampling was conducted based on the various areas in Dhaka city
is an accessory for RAD 7, not a detector Corrected 1, 22-23
What are the effective digits for clarifying the concentrations? We changed the effective
digit to be two instead of three in the revised manuscript.
What is MCL? We added the term ‘the maximum contamination limit (MCL) or maximum contaminant
level (MCL)’ in the revised manuscript.
1, 25
Why two standards (diverse in recommended units) are clarified?
Why not- safe limit as set by UNSCEAR? UNSCEAR safe limit also be added. Since limits
are given by several organizations, we used two of them. 10, 260-262
not needed for Bangladesh? Line deleted
1) Problem oriented background has not been described in the text? what are the scientific
purposes?
2) As of first time obtained data, it is important to ascertain the radon level in
water in Dhaka city, however, it would be better to make some statistical analysis
to determine how the obtained data from different sources are significant and associated
with each other.
3) The dose calculation might be wrong 1) Respected reviewer, in the abstract we
mentioned as follows ‘Radon (222Rn), an inert gas, is considered a silent killer due
to its carcinogenic characteristics. Dhaka city is situated on the banks of the Buriganga
River, which is considered the lifeline of Dhaka city because it serves as a major
source of the city's water supply for domestic and industrial purposes.’.
Also, in the introduction we mentioned as follows ‘Numerous studies have been performed
worldwide to measure the 222Rn level in various water resources such as tap water,
river water, deep well water, bore well water, bottled water, etc.(Faweya et al.,
2021; Mustapha et al., 2002; Rani et al., 2021; Thumvijit et al., 2020; Yong et al.,
2021). Bangladesh has no such reference level for 222Rn in water. Millions of people
living in the Dhaka megacity solely rely on tap water for their daily household purposes,
such as washing, bathing, drinking, cooking, etc. The Buriganga river serves as one
of the busiest major transportation routes/hubs, as well as many businesses and trade
centers that are situated on the bank of this river. This indicates a greater possibility
of 222Rn exposure to the general populace. So, it is necessary to measure the 222Rn
level in the tap water and the Buriganga river water to find out if it is within the
safe limit or not, which eventually will help to ensure the radiological safety of
public health.’
2) Thank you for your valuable comment. Instead of doing a separate statistical analysis
to obtain the correlation between the sources, we simply reported the mean, range,
standard deviation of the measured values, and we assume that this is an acceptable
approach for the present results. This is because, both sources show a low range of
values (overall, the data of river water is relatively lower than the data of tap
water, which is obvious because of aeration issue of river water).
3) Thank you, the value of 730 L/d has been corrected. It was mistake, it should be
730 L/y
Emanation is from soil/materials with having grain? Corrected. We changed the term
‘emanates’ into ‘escapes’ in the revised manuscript. 2, 47
According to international institutes like EPA, radon is not a direct contaminant
for safe water.
https://www.epa.gov/dwreginfo/drinking-water-regulations
https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations#Radionuclides
https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=30006644.txt Line deleted
Radon- a leading cause of lung cancer; at this present days, consideration radon as
2nd cause is possibly under discussion
https://www.who.int/news-room/fact-sheets/detail/radon-and-health
https://erj.ersjournals.com/content/erj/48/3/889.full.pdf
https://www.wcrf.org/diet-activity-and-cancer/cancer-types/lung-cancer/ Line deleted
IAEA reference? We removed the term ‘IAEA’ from the line 3, 72-73
References are needed Line deleted
There are numerous studies concerning, radon measurement in air for Bangladesh.
Farid, S. M. (1993a). Equilibrium factor and dosimetry of
radon by CR-39 nuclear track detector. Radiation Pro_tection Dosimetry, 50(1), 57–61.
https://doi.org/10.
1093/oxfordjournals.rpd.a082065
Farid, S. M. (1993b). Measurement of concentrations of
radon and its daughters in indoor atmosphere using
CR-39 nuclear track detector. Nuclear Tracks And Radi_ation Measurements (1993), 22(1–4),
331–334. https://
doi.org/10.1016/0969-8078(93)90079-J … … … Line deleted
Irrelevant to this study Line deleted
Reference is needed Line deleted
The potential cause of radon exposure through tap water and river water has not been
logically clarified.
-It would be better to clearly clarify the possible potential risks factors of radon
exposure in water- radionuclide contents in river soil or sediment, geology of Dhaka
city based on previous studies Some possible potential risk information has been added
in the revised manuscript
1) It is important to insert scientific purposes: reason of variation in radon concentrations
in different locations in Dhaka city; comparative discussion/statistical analysis
between characteristics/level of tape water and river etc.,
2) As this research has not determined any chemical or biological effect of Buriganga,
why them come in the first purpose 1) Respected reviewer, it has been mentioned in
the abstract as well as in the later part of introduction. Also, the same response
to your comment no. 3
2) Just to show the hazardous nature of radon
Overall, the introduction part is much larger with introduction or radon, its limits,
characterization; however, the information regarding the important/background of radon
study in water in Dhaka has not sufficiently addressed. We tried to present a complete
story of radon, its sources, hazardous nature and then background of the study
Through the discussion of study area and specially the geological discussion of Dhaka
city; nothing has been clarified about the potential radon risks in Dhaka city.
1)Why and how the measurement area and sampling positions have been chosen, not clarified.
2) Geology of Dhaka city was nicely addressed, however, nothing was mentioned about
radon based on that; it seems that there is no relationship with the title in 2.2.
Please see the above response
Reliable reference should be added for scientific paper Corrected 4, 95
This is not a format of writing reference Corrected 4, 99
In the results/discussion section, there is not sufficient discussion about radon
distribution based on geological impact We added a section named “2.3 Radiological
risks based on geology” in the revised manuscript. 6, 150
Please specify what criteria were filled up collecting water samples avoiding escaping
radon.
What type of plastic bottle was used and what arrangement were taken for bottle cap?
https://www.iaea.org/sites/default/files/19/11/radon-presentation-bochicchio.pdf The bottle was fully submerged into the water during collecting the samples. After
filling, the bottle was sealed instantly under the water without any water bubble.
The laboratory standard plastic bottles were used. The caps of the bottles were flexible
and sealed tightly. We analyzed the water in the glass bottles within few hours of
collecting water.
How about lower detection limit of the detector? The RAD H2O is an attachment for
the RAD7 that allows measuring radon in water at concentrations above the minimum
detectable activity (MDA). The MDA concentration of this instrument is 0.004 Bq/L
Below the lower detection limit? The MDA concentration of this instrument is 0.004
Bq/L
Is it possible reason for Bangladesh?
for comparison, WHO or ESEPA; which is more suitable for Bangladesh? Difficult to
give preference to one another
Why these references are inserted instead of WHO or USEPA? Added WHO and USEPA references
10, 260-262
Why the effective dose for radon for ingestion and inhalation is same?
The other studies from other countries(cited in this article) possess much difference
We have corrected the dose calculation in the revised manuscript. We used Eq 1 and
2 for calculating ingestion and inhalation doses, respectively. In Eq. 1, we used
EDC (Effective Dose Coefficient) = 3.5 nSv/Bq for 222Rn ingestion (UNSCEAR, 2010),
CW (daily water consumption) = 3 L/day (Rani et al., 2021; WHO, 2017), but in other
studies, they used different values for EDC and CW for calculating ingestion doses.
For calculating inhalation doses by using Eq 2, we used DCF (dose conversion factor
for 222Rn exposure) = 9 nSv(hBqm-3)-1 (UNSCEAR, 2010). But different values of DCF
were used in other papers. We found the ingestion and inhalation doses different using
the values mentioned earlier.
effective digits changed the effective digit to be two 10, 256-257
only 1 reason is mentioned There might be many, but the most important one has been
mentioned
How the results are consistent? According to the Table 3, this study showed a similar
results of radon concentration in the Buriganga river water (0.68 ± 0.29 Bq/L) with
Karnataka, India (0.16 - 1.79 Bq/L) (Rajashekara et al., 2007), Hemavathi River India
(0.67 Bq/L) (Shivanandappa & Yerol, 2018), Kirkuk, Iraq (0.359Bq/L ) (Kareem et al.,
2020). The line has been modified in the revised manuscript like this this (Page No.
12, Line No. 286-289), “Additionally, the result of this study is consistent with
the previous research carried out in different regions of the world, such as in Karnataka,
India (0.16 - 1.79 Bq/L) (Rajashekara et al., 2007), Hemavathi River India (0.67 Bq/L)
(Shivanandappa & Yerol, 2018), Kirkuk, Iraq (0.359Bq/L ) (Kareem et al., 2020).”
Isn’t is this study? Corrected 15, 346
Not a detector, it is an accessory Corrected 15, 337
due to radon in water included 15, 347
Why? This study have not identify any potential exposure of radon in water? Line deleted
IAEA recommended to focus on air radon concentrations rather than radon in water to
set the national reference level. Line deleted
Authors could not be found in the website.
-Is the journal a reliable source for scientific papers?
-Reference was done written correctly Properly Cited
It was published it 2011 Corrected
Why same reference has been inserted for two time as a and b? Properly cited
1) In Journal of Chemical Information and Modeling, Vol. 53, Issue 09;
https://pubs.acs.org/toc/jcisd8/53/9
There is not any report/article concerning Bangladesh/its population.
2) Why two sources, Bureau and journal inserted in same reference?
3) There is no clarification of page number of the journal
Changed the citation
187, 4075 The line containing this citation was deleted
This is not a suitable source/reference for scientific journal papers
Changed the citation
No title of paper; cannot be found in website Changed the citation
Some reference has short form of name; many have full name Properly cited
(1) was not found in website
https://link.springer.com/article/10.1007/s10967-020-07349-5#citeas Properly cited
a reliable source? Banglapedia is a national encyclopedia which is a reliable source
of information and suitable for scientific journals.
Researchgate is not a source of reference Properly cited
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