(a) Service connection based on presumed exposure to fine particulate matter -
(1) General. Except as provided in paragraph (b) of this section, a disease listed in paragraphs (a)(2) and (a)(3) of this section shall be service connected even though there is no evidence of such disease during the period of military service.
(2) Chronic diseases associated with exposure to fine particulate matter. The following chronic diseases will be service connected if manifested to any degree (including non-compensable) within 10 years from the date of separation from a qualifying period of military service as defined in paragraph (a)(5) of this section.
(i) Asthma.
(ii) Rhinitis.
(iii) Sinusitis, to include rhinosinusitis.
(3) Rare cancers associated with exposure to fine particulate matter. The following rare cancers will be service connected if manifested to any degree (including non-compensable) at any time following separation from a qualifying period of military service as defined in paragraph (a)(5) of this section.
(i) Squamous cell carcinoma of the larynx.
(ii) Squamous cell carcinoma of the trachea.
(iii) Adenocarcinoma of the trachea.
(iv) Salivary gland-type tumors of the trachea.
(v) Adenosquamous carcinoma of the lung.
(vi) Large cell carcinoma of the lung.
(vii) Salivary gland-type tumors of the lung.
(viii) Sarcomatoid carcinoma of the lung.
(ix) Typical and atypical carcinoid of the lung.
(4) Presumption of exposure. A Veteran who has a qualifying period of service as defined in paragraph (a)(5) of this section shall be presumed to have been exposed to fine, particulate matter during such service, unless there is affirmative evidence to establish that the veteran was not exposed to fine, particulate matter during that service.
(5) Qualifying period of service. The term qualifying period of service means any period of active military, naval, or air service in:
(i) The Southwest Asia theater of operations, as defined in § 3.317(e)(2), during the Persian Gulf War as defined in § 3.2(i).
(ii) Afghanistan, Syria, Djibouti, or Uzbekistan on or after September 19, 2001 during the Persian Gulf War as defined in § 3.2(i).
(b) Exceptions. A disease listed in paragraph (a)(2) and (3) of this section shall not be presumed service connected if there is affirmative evidence that:
(1) The disease was not incurred during or aggravated by a qualifying period of service; or
(2) The disease was caused by a supervening condition or event that occurred between the Veteran's most recent departure from a qualifying period of service and the onset of the disease; or
(3) The disease is the result of the Veteran's own willful misconduct.
[87 FR 24429, Apr. 26, 2022]