; (2) the frequency of sampling continuous personal dust monitors should be increased; (3) engineering controls and work practices used by mine operators to achieve and maintain the required respirable coal mine dust levels should be modified; and (4) samples taken on shifts longer than 8 hours should be converted to an 8-hour equivalent concentration to protect miners who work longer shifts. (b) Report (1) Initial report Upon beginning the study under subsection (a), the Secretary of Labor shall transmit a copy of such study to Congress, notifying Congress that such study has commenced. (2) Annual reports For each year after the commencement of the study under subsection (a) and until such study is completed, the Secretary of Labor shall transmit a report to Congress on the progress of such study. (3) Final report Upon completion of the study under subsection (a), the Secretary of Labor shall submit a final report of such study to Congress. 505. Refresher training on miners’ rights and responsibilities (a) In general Section 115(a)(3) ( 30 U.S.C. 825(a)(3) ) is amended to read as follows: (3) all miners shall receive no less than 9 hours of refresher training, no less frequently than once every 12 months. Such training shall include one hour of training on the statutory rights and responsibilities of miners and their representatives under this Act, and other applicable Federal and State law, and shall be through a program of instruction developed by the Secretary and delivered by an employee of the Administration (or a trainer approved by the Administration) that is a party independent from the operator; . (b) National hazard reporting hotline Section 115 ( 30 U.S.C. 825 ), as so amended, is further amended— (1) by redesignating subsections (c) through (e) as subsections (d) through (f), respectively