Pollution Characteristics, Chemical Compositions, and Population Health Risks during the 2018 Winter Haze Episode in Jianghan Plain, Central China

Round 1

Reviewer 1 Report

The authors have sufficiently satisfied my concerns.

Reviewer 2 Report

Thank you for considering my suggestions. My comments have been adequately responsed.

A small note is that the scientific notation (1.6E-7) should be replaced with the readable notation (as in lines 434-435.) in section 3.4.1 and in Table 2.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The authors have collected PM2.5 samples over a 10 day period in 2018 focused on Xiantao in JHP, Central China. This coincided with a severe pollution period. The authors present results on composition including PM-bound metal(loid)s. Health risks were also calculated based on exposure concentrations. Although an interesting paper with some new data there are gaps that need to be addressed to provide better context of the findings. Comments below. 

- The authors reported that 51% of the GDP is allocated as industry. Although no further details are provided. What are these industries? Where are they located? Is it possible that these were near sources impacting the filters? All this information was not provided.

-The authors focused on 10 days in January. An extremely small sample size and thus requires some context of which the authors did not provide. How representative is this episode of the region and of a high pollution event? What are the ranges of concentrations seen normally without pollution events there in January? How does the high pollution event you measured compared to other high pollution events that have occurred there?

- how often is there a haze event in this region?

- Where is the Hubei met site relative to the sampling location. How far is is? Is it sited to represent ambient meteorology and thus may not be relevant for your location of measurements. No discussion on this was presented. 

-The authors focused on 10 days in January. An extremely small sample size and thus requires some context of which the authors did not provide. How representative is met conditions during this period 

- I have several issues with the risk calculation that need to be clarified in the text. The exposure, especially during the high pollution event, is an acute one. Are the risk factors you have calculated based on chronic or acute exposures? Can explanation be provided on justification of applying chronic risks to an acute exposure? And what those results mean given the short exposure times.

Line 195 - how were these levels chosen and what is the sample number per bin? How do they compare with historical values in the area. It would perhaps be more meaningful to bin by high pollution and “normal” levels, and elevated levels based on historical data. 

Figure 2- It would be nice to have resultant Wind speed and direction on this figure. The resultant winds could be time matched with the bins of time. Could the authors spend some time discussing jan13 and why TE was constant? Is that real or an artifact? Missing data on jan 21? This compositional analysis is useful. Were there any correlations with changes in mass and the constituents? What about the industry found in the area, what would their emissions profile look like and how does that compare to the results you have. Can something be said based on composition about the contribution of local sources? On line 261 you suggest mobile is a large contributor, local mobile or long range?

Figure 3 - I am not sure how useful the Hysplit plots are. Although good for determining long range transport into the region the authors have not shown how much is the contribution of local versus long range transport. Using hourly local met wind speed and direction  the authors could draw displacement of plumes and track the trajectory over much finer spatial detail. Do these displacement place the path of the trajectory over local industrial sources? 

Line 304 - this is an interesting result and I feel the authors have only provided a cursory analysis of this. Is this common to haze events, in the area or elsewhere? How does this compare to other correlations? What were the industrial sources and met conditions that could lead to this?

Line 314 - the first time that local industry may be impacting results. Seems out of place here and requires more expansion of this analysis. 

Figure 6 - could you add the Lgeo levels for degree of contamination on 6a; Not sure 6b works here paired with 6a? Figure 6b this maybe e easier to read if you sorted the elements by highest to lowest risk 

Table 2 - could this be sorted such that the highest  ADPED are at the top

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript reports valuable data obtained from an extensive measurement campaign. The results provide important information in an area facing heavy air pollution issues. Therefore, I recommend this manuscript for publication after a few minor issues have been considered.

My general comment is that this research is more related to environmental chemistry and health than atmospheric sciences. A journal focusing on Environmental Science and Public Health might better suit this research than Atmosphere.

While the chemical analysis is well presented, the public health assessment needs more elaboration both in the Methods and the Discussion. Please provide a table of values applied for the variables in Eqs. 2-4. Some sensitivity or uncertainty assessment of these values would also be necessary, e.g. what is the range of different ingestion, inhalation rates among different population groups? What habitual, lifestyle factors were considered in the definition of these paremeters? It would be reader-friendly to see a summary of these important methodological details without researching the given four references, including the EPA handbook. 

„The TCR values were approximately 1.12-fold higher for adults than for children” – what is the reason behind this? Children are generally considered to be the more vulnerable group for air pollution. This is a surprising result that requires more discussion.

Minor comments:

line 34: PM2.5, with strong dependence on its composition and other details, is assumed to have a negative net effect on global climate. Please provide more explanation, citation or remove the phrase “adverse effect on global climate change”. The cited reference [2] has no relevance in this context.

please use space between numbers and units, e.g. “20 m”

Figure 1 might require to include a Google and other logos according to the Google Earth license. Please check.

line 205: Turkey

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript presents filter-based measurements of PM2.5 mass and composition, followed by exposure calculations meant to relate pollution levels to human health effects.  Overall, the work might be useful to the community, but this manuscript doesn’t really tell us anything new.  A paper currently in press has the same exact analysis for measurements performed at the same exact time from a city about 300 km away which was experiencing the same exact haze episode.  Thus, what exactly is new here?

No analysis was done to compare the 2 cities (actually, there are more cities listed in Table 1 that have the same sample periods).  A paper with a different analysis which includes multiple cities would be considered new.

I include some comments below which I was writing out to assist the authors on this manuscript, but I have stopped about half way through.  After discovering how similar this manuscript is to the article in press, I do not believe this manuscript should also be published and, thus, have abruptly stopped providing my feedback.

General comments: 

First, a thorough proofreading for spelling and grammar is necessary.  There are quite a few mistakes throughout the manuscript (too many to list them all - though a few specific ones are provided below). 

Grammatically, check for use of proper articles (“a, an, the”). 

Grammatically, check for proper use of singular and plural nouns. 

Grammatically use consistent tense, and in some cases change past tense to present tense. 

Avoid repetition and long run-on sentences.   

I am not familiar with using “NWN”.  Typically this would be “NNW”.  In Figure 3, however, the green trajectory comes from the North immediately over the site, and from the W further upwind.  In total, the source of the green trajectory is not very different than the red trajectory, which you’ve labeled “NW”.  The discussion about these airmass directions needs to be made more clear.

Why is the term “metal(oid)s” used throughout?  I’m not familiar with this presented this way.  What is the difference between and “metal”, “metaloid”, and “metal(oid)”?

To calculate the geo-accumulation index, where do you get values for Ci_crust?  Did you sample this yourself?

For the exposure model calculations, be more clear about where all the constants and factors come from and how they are determined.  There are several papers cited, but you should include enough details in this paper that I don’t have to go read them all to understand your methods.

Specific comments:

Line 25-26 - not a complete sentence

Line 88, 126 - What is the meaning of “filed blank samples”?  How were the blanks collected, specifically?  Using the term “filed” indicates that these were not actually collected in the field but have just been ‘filed away’ or stored in the lab somehow.  Line 127 then uses the term “field blanks” - so maybe this is a typo.

Line 95 - not a complete sentence

Line 96 - What does “(on trial)” mean?

Line 145-146 - I don’t understand the use of the constant (1.5), why its necessary, and what “verify the natural fluctuations” mean.  Please clarify and provide more details.

Line 163 - Are these Ci in the equations the same as in equation 1?  Be more clear.

Line 205 and Table 1 - “Turky” is misspelled

Line 234 - “SNA” is used before it is defined

Line 238 - “air quality levels increased” is odd terminology; air quality can be poorer or improved

Line 262 - “SOR” and “NOR” are not defined in this paper; they are defined in the other paper

Author Response

Please see the attachment.

Author Response File: Author Response.docx