Tyre Weights an Overlooked Diffuse Source of Lead and Antimony to Road Runoff

Round 1

Reviewer 1 Report

In the manuscript entitled “Tyre weights an overlooked diffuse source of lead and antimony to road runoff”, M. Taylor et al.  have evaluated the effect on the dispersion in the environment of lead and antimony caused by the type, number and weight of tyre weights lost from motor vehicle for a range of roading infrastructures and motor vehicle intensities along a 6.9 km in a length of road in Hamilton City, New Zealand, during 38 months.

In my opinion, the abstract is too long, it should be reduced, focalizing on the motivation of the reported study and on the best obtained results.

I suggest to add to the keywords “tyre” and “lead and antimony”.

In the introduction, the authors should briefly indicate in which manner the content of Pb and Sb have been examined; moreover, they should refer to similar studies reported in literature.

Have the authors study the emission of residues released by different type of tyres? It would be interesting to evaluate the tyre composition and correlate it to the released pollutants.

The procedure used to associate the emission/presence on the concrete of Pb and Sb has not been explained; please, discuss.

How can you be sure that the all Pb and Sb released came from tyre? It is not clear; please, discuss.

In my opinion, the authors should conduct a reference experiment: a) evaluation of the release of Pb and Sb from the rolling of the tyre on a piece of reference road after a tot number of rolling; b) evaluation of the remaining total content of Pb and Sb by by acid digestion, destroying the tyre and correlating it with the reported data in datasheet of the tyre.

The chemical methodology used to detect and analyse the Pb and Sb content is not clear; please, add and discuss.

I suggest also to correlate the data not only to the weight of the vehicle but also with its velocity and to other parameters, such as the tyre temperature, etc. Please, discuss.

 

In my opinion, the reported study has a big lack in the procedure used to estimate the released content of Pb and Sb, not any analytical methodology has been discussed; therefore, on the basis of the reported study it is not possible to estimate the pollutant quantity and to univocally associate it to the tyre release.

 

Comments for author File: Comments.pdf

Author Response

See word file attached

Author Response File: Author Response.docx

Reviewer 2 Report

The topic is interesting, and the duration of the experiment is sufficient. However, I have comments on the work that I have included in the following.

The description of the methodology is insufficient.
L93, L94 the methodology should be clarified, the description is not completely understood. No details on the distribution used in the studies, L169-170.
The reader will not find information whether the selection of the section of the route was representative in relation to the larger area.
Has independent routine cleaning included in the study - road sweeping that may have affected data, missing information
Whether some of the material did not get into the road inlets - it should be discussed.

L128 - what is the specific information in Figure 1. There was no interpretation of box charts. No explanation of the markings in the drawing.
L130 - L137 in my opinion, there is no other statistical tool to determine the phenomenon's trends.
The conclusions (L 228) essentially repeat the content of the previous chapter. The applications should be reworded.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The authors present a very thorough study about the impact of lead tyre weights in the environment. They use a sound methodology to estimate the amount of Pb and Sb that is released in the environment through the loss of tyre weights. This is a very simple yet very interesting and new study, providing a detail account of a mostly understudied part of the biogeochemical cycle of these two toxic elements. The global amounts estimated from their measurements are sound and perfectly justified. The conclusion are well supported by the results. This manuscript should be accepted once the very minor issues listed below are addressed.

There are very minor spelling mistakes in line 12: "legacy b from", line 66-67: "on an imperviousness surface", line 75: "programmes. [24] collected", line 213: "We agree) that".

Figure 1 does not contain any unit for the weights

Figure 2 and 3 and directly taken from Excel and I strongly suggest that the authors spend a bit of time to produce higher quality figures in line with what is usually found in scientific articles.

Author contribution paragraph is not filled.

 

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

In this manuscript, Taylor and Kruger have studied on the amount of Pb and Sb pollution on New Zealand roads from the vehicle tyres. It is reported that the annual deposition of Pb and Sb deposited on urban local roads are 14400 kg and 760 kg, respectively. As an alternative of the “Lead” tyre, Al or Fe is suggested as these are environmentally benign and are already major constituents of soil. This manuscript is interesting and useful for future research. This manuscript could be accepted.

Author Response

Thankyou for your review

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Dear Autors,

Thank you for the detailed explanation.

 

Yours sincerely