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###### Environmental Protection Agency

          - [Docket ID No. EPA-HQ-ORD-2014-0859; FRL-9002-01-ORD]

# AGENCY:

Environmental Protection Agency (EPA).

# ACTION:

Notice of availability.

# SUMMARY:

                        The Environmental Protection Agency (EPA) is announcing the availability of a draft document titled, “Supplement to the 2019 Integrated Science Assessment for Particulate Matter (External Review Draft)” (EPA/600/R-21/198). The document was prepared by the Center for Public Health and Environmental Assessment (CPHEA) within EPA's Office of Research and Development (ORD) as part of the reconsideration of the 2020 National Ambient Air Quality Standard (NAAQS) for particulate matter (PM). The Supplement represents a targeted review of peer-reviewed studies published since the literature cutoff date (                        *i.e.,*                         ~January 2018) of the 2019 Integrated Science Assessment for Particulate Matter (PM ISA). The Supplement and the 2019 p.m. ISA provide the scientific basis for EPA's decisions, in conjunction with additional technical and policy assessments, for the reconsideration of the current NAAQS and the appropriateness of possible alternative standards. EPA is releasing this draft document to seek review by the Clean Air Scientific Advisory Committee (CASAC) and the public. In addition, the date and location of a public meeting for CASAC review of this document will be specified in a separate                         **Federal Register**                         document. This draft document is not final and it does not                               ( print page 54187)                            represent, and should not be construed to represent, any final Agency policy or views. When revising the document, EPA will consider any public comments submitted during the public comment period specified in this notice.                    

# DATES:

Comments must be received on or before November 29, 2021.

# ADDRESSES:

                        The “Supplement to the 2019 Integrated Science Assessment for Particulate Matter (External Review Draft)” will be available primarily via the internet on EPA's Integrated Science Assessment Particulate Matter page at                         *https://www.epa.gov/​isa/​integrated-science-assessment-isa-particulate-matter*                         or the public docket at                         *http://www.regulations.gov,*                         Docket ID: EPA-HQ-ORD-2014-0859. A limited number of CD-ROM copies will be available. Contact Ms. Christine Alvarez by phone: 919-541-3881; fax: 919-541-5078; or email:                         *alvarez.christine@epa.gov*                         to request a CD-ROM, and please provide your name, your mailing address, and the document title, “Integrated Science Assessment for Particulate Matter” to facilitate processing of your request.                    

# FOR FURTHER INFORMATION CONTACT:

                        For information on the public comment period, contact the ORD Docket at the EPA Headquarters Docket Center; phone: 202-566-1752; fax: 202-566-9744; or email:                         *Docket_ORD@epa.gov.*

                        For technical information, contact Mr. Jason Sacks, CPHEA; phone: 919-541-9729; fax: 919-541-1818; or email:                         *sacks.jason@epa.gov.*

# SUPPLEMENTARY INFORMATION:

## I. Information About the Document

                    Section 108(a) of the Clean Air Act directs the Administrator to identify certain pollutants which, among other things, “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare” and to issue air quality criteria for them. These air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of [a] pollutant in the ambient air . . .” Under section 109 of the Act, EPA is then to establish NAAQS for each pollutant for which EPA has issued criteria. Section 109(d) of the Act subsequently requires review every five years and, if appropriate, revision of existing air quality criteria to reflect advances in scientific knowledge on the effects of the pollutant on public health or welfare. EPA is also required to review and, if appropriate, revise the NAAQS, based on the revised air quality criteria (for more information on the NAAQS review process, see                     *http://www.epa.gov/​ttn/​naaqs/​review.html*).                

PM is one of six criteria pollutants for which EPA has established NAAQS. Periodically, EPA reviews the scientific basis for these standards by preparing an ISA (formerly called an Air Quality Criteria Document). The ISA, and this Supplement, provide the scientific basis for EPA's decisions, in conjunction with additional technical and policy assessments, on the adequacy of the current NAAQS and the appropriateness of possible alternative standards. The Clean Air Scientific Advisory Committee (CASAC), an independent science advisory committee whose review and advisory functions are mandated by Section 109(d)(2) of the Clean Air Act, is charged (among other things) with independent scientific review of the EPA's air quality criteria.

On December 3, 2014 (79 FR 71764), EPA formally initiated its current review of the air quality criteria for the health and welfare effects of particulate matter and the primary (health-based) and secondary (welfare-based) NAAQS, requesting the submission of recent scientific information on specified topics. EPA conducted a workshop from February 9 to 11, 2015 to gather input from invited scientific experts, both internal and external to EPA, as well as from the public, regarding key science and policy issues relevant to the review of the primary and secondary NAAQS (79 FR 71764). These science and policy issues were incorporated into EPA's “Draft Integrated Review Plan for the National Ambient Air Quality Standards for Particulate Matter,” which was available for public comment (81 FR 22977) and discussion by the CASAC via publicly accessible teleconference consultation (81 FR 13362). The “Final Integrated Review Plan for the National Ambient Air Quality Standards for Particulate Matter” was released December 6, 2016 (81 FR 87933).

                    Subsequent webinar workshops were held on June 9, 13, 20, and 22, 2016, to discuss initial draft materials prepared in the development of the particulate matter ISA with invited EPA and external scientific experts (81 FR 29262). The input received during these webinar workshops aided in the development of the materials presented in the “Integrated Science Assessment for Particulate Matter (External Review Draft), which was released on October 23, 2018” (83 FR 53471), and is available at:                     *https://cfpub.epa.gov/​ncea/​isa/​recordisplay.cfm?​deid=​341593.*                     The CASAC met at a public meeting on December 12—13, 2018 (83 FR 55529), to review the draft PM ISA. A public teleconference was then held on March 28, 2019 for CASAC to review their draft letter to the Administrator on the draft ISA. This meeting was announced in the                     **Federal Register**                     on March 8, 2019 (84 FR 8523). Subsequently, on April 11, 2019, the CASAC provided a letter of their review to the Administrator of the EPA, available at:                     *https://yosemite.epa.gov/​sab/​sabproduct.nsf/​264cb1227d55e02c85257402007446a4/​6CBCBBC3025E13B4852583D90047B352/​$File/​EPA-CASAC-19-002+​.pdf.*                     The letter from the CASAC, as well as public comments received on the draft PM ISA, can be found in Docket ID No. EPA-HQ-ORD-2014-0859.                

                    The Administrator responded to the CASAC's letter on the External Review Draft of the PM ISA on July 25, 2019, and is available at:                     *https://yosemite.epa.gov/​sab/​sabproduct.nsf/​264cb1227d55e02c85257402007446a4/​6CBCBBC3025E13B4852583D90047B352/​$File/​EPA-CASAC-19-002_​Response.pdf.*                     The PM ISA was finalized on December 31, 2019, and its availability announced in a January 27, 2020                     **Federal Register**                     document (85 FR 4655). On December 7, 2020, after reviewing the most recent available scientific evidence and technical information, and consulting with the Agency's independent scientific advisors, EPA announced its decision to retain, without revision, the existing primary (health-based) and secondary (welfare-based) PM NAAQS.                

                    On June 10, 2021, EPA announced it will reconsider the December 2020 decision to retain the PM NAAQS and as part of this process develop a supplement to the 2019 Final Integrated Science Assessment (ISA), available at:                     *https://www.epa.gov/​newsreleases/​epa-reexamine-health-standards-harmful-soot-previous-administration-left-unchanged.*

                    The “Supplement to the 2019 Integrated Science Assessment for Particulate Matter (External Review Draft)” will be discussed at a public meeting for review by CASAC. In addition to the public comment period announced in this document, the public will have an opportunity to address CASAC at this meeting. A separate                     **Federal Register**                     document will inform the public of the exact date and time of the CASAC meeting and of the procedures for public participation.                

##                     II. How To Submit Technical Comments to the Docket at                     *www.regulations.gov*

                    Submit your comments, identified by Docket ID No. EPA-HQ-ORD-2014-0859, by one of the following methods:                          ( print page 54188)    
    -  www.regulations.gov:                      Follow the online instructions for submitting comments.                
    -  Email: Docket_ORD@epa.gov. 
    -  Fax:                      202-566-9744. Due to COVID-19, there may be a delay in processing comments submitted by fax.                
    -  Mail:                      U.S. Environmental Protection Agency, EPA Docket Center (ORD Docket), Mail Code: 28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460. The phone number is 202-566-1752.                

*Note:*                     The EPA Docket Center and Reading Room may be closed to public visitors to reduce the risk of transmitting COVID-19. Docket Center staff will continue to provide remote customer service via email, phone, and webform. The public can submit comments via                     *www.Regulations.gov*                     or email. No hand deliveries are currently being accepted.                

The EPA Docket Center and Reading Room is currently in the reopening process. Visitors may be considered on an exception basis. Visitors must complete docket material requests in advance and then make an appointment to retrieve the material. Visitors will be allowed entrance to the Reading Room by appointment only, and no walk-ins will be allowed.

The EPA continues to monitor information carefully and continuously from the Centers for Disease Control and Prevention (CDC), local area health departments, and our Federal partners so that we can respond rapidly as conditions change regarding COVID-19.

*Instructions:*                     Direct your comments to Docket ID No. EPA-HQ-ORD-2014-0859. Please ensure that your comments are submitted within the specified comment period. Comments received after the closing date will be marked “late,” and may only be considered if time permits. It is EPA's policy to include all comments it receives in the public docket without change and to make the comments available online at                     *www.regulations.gov,*                     including any personal information provided, unless a comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information through                     *www.regulations.gov*                     or email that you consider to be CBI or otherwise protected. The                     *www.regulations.gov*                     website is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to EPA without going through                     *www.regulations.gov,*                     your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at                     *http://www2.epa.gov/​dockets.*

*Docket:*                     Documents in the docket are listed in the                     *www.regulations.gov*                     index. Although listed in the index, some information is not publicly available,                     *e.g.,*                     CBI or other information whose disclosure is restricted by statute. Certain other materials, such as copyrighted material, are publicly available only in hard copy. Publicly available docket materials are available either electronically on                     *www.regulations.gov*                     or in hard copy at the ORD Docket in the EPA Headquarters Docket Center.                

Timothy Watkins,

Acting Director, Center for Public Health and Environmental Assessment.

[FR Doc. 2021-20504 Filed 9-29-21; 8:45 am]

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