Figures
There is an error in affiliation 3 for author Andee Krasner. The correct affiliation 3 is: Independent Public Health Consultant, Boston, Massachusetts, United States of America.
In Table 1, all values in Column 6 entitled “Standard Error” are miscalculated. Please see the correct Table 1 here.
In S1 Appendix, most values in Column 8 of Table 4, entitled "“Third Floor Minus Outdoor Gas,” are incorrect. It can be viewed below.
Supporting information
S1 Appendix. Instrument calibration check.
We tested the analyzer prior to the beginning of the survey, on February 29, 2024; during a midpoint of the survey, on April 23, 2024, and near the conclusion of the survey on June 19, 2024, against nominal 0.0 ppm; 2.0 ppm and 10 ppm test gasses in ultrapure air. The test gas tanks (Scott-Marrin, Riverside, CA USA) were certified to contain < 0.01 ppm; 2.072 ppm; and 10.32 ppm [CH4] respectively (+/- 1% NIST). Test gasses were supplied to the analyzer using Tedlar bags filled with test gasses and connected to the analyzer inlet during normal operation. Tedlar bags of test gas supply were maintained until the graphical data display indicated the analyzer [CH4] reading stabilized near the nominal value. Table 3 shows the match between analyzer values of [CH4] and test gas values. These results demonstrate that our analyzer was working properly and with adequate precision for the study.
https://doi.org/10.1371/journal.pone.0357112.s001
(DOCX)
Reference
Citation: Phillips NG, Ackley R, Krasner A (2026) Correction: Indoor methane consistently above outdoor levels in homes with natural gas service. PLoS One 21(8): e0357112. https://doi.org/10.1371/journal.pone.0357112
Published: August 26, 2026
Copyright: © 2026 Phillips et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.