Semiquantitative photochromic dosimetry of UV-C exposure in classrooms, dental clinics and restrooms: an exploratory experimental study
Cristel Francely Miranda Lazo, Lindy Pahola Loza, Jennifer López González, Elba Cristalia González, Axel Alejandro Gámez Guerrero, Pedro Josué Zepeda Espinoza, Alexa Isabella Nicaragua Casaya, Elmer Francisco Baltodano Mejia, Michelle Murillo Sánchez, Bertha Abigail Espinoza Manzanarez, Helen Viviana Cajina Balmaceda, Kristel Dariana Amador Murillo, William Morales Bermúdez, Ilfred Mercedes Reyes Jaime, Emily Isabel Vargas, Keysi Javiera Conto Baltodano, Dubraska Isabel Estrada Márquez, Javier Antonio Chávez Treminio, Jannys Marcela Betancour Urbina, Shirly María Moya Arguello, Gloria Elena Duarte Morales, Ligia Elena Ordóñez Alemán, María José Guadamúz Selva, María Mercedes Rocha Trujillo, Steyssis Guadalupe Berrios Chávez, Alejandra Massiel Dauria Vivas, José Alfonso Castillo Rosales, Franchesca Marie Tercero Sánchez, Fátima Geraldina Chorro Bermúdez, Meyling Ignacia Arley Córdoba, Kevin Alexandro Cazorla Lata, William Conrado, Silvio Alejandro Ortega Chow, Amanda Leticia Vega FongObjective. To characterize UV-C dosimetric readings across indoor surfaces and compare them with nominal targets and calculated exposure.
Methods. An exploratory experimental study with descriptive analysis was conducted in 2022 in classrooms, dental clinics and restrooms in Managua, Nicaragua. Twelve series used single-use UVCiX cards read visually. An HP350UVS electronic source-characterization spreadsheet was incorporated. Electronic irradiance, poster-reported values, calculated doses and visual readings were distinguished.
Results. Fourteen numerical readings from eight series supported the dosimetric description; ten allowed comparison with nominal targets. In G1, poster-reported irradiances yielded 97.2 mJ/cm² at both positions; cards indicated 90–100 mJ/cm² at 1 m for 15 min and 50–75 mJ/cm² at 2 m for 30 min. Another classroom yielded 35, 10–15 and 10–15 mJ/cm² after 30 min. Dental readings included 40 mJ/cm² after 10 min and 75 and 150 mJ/cm² after 37 min. Reading-to-target ratios ranged from 10.0 to 125.0%. The spreadsheet placed 0.021 mW/cm² at 2.5 m, whereas dental posters placed it at 1 m.
Conclusions. Indicator responses varied across positions and conditions, including conditions with equal calculated exposures. The study provides a surface-specific dosimetric comparison that distinguishes electronic measurement, calculation and visual reading. Its semiquantitative scope characterizes physical exposure and does not evaluate microbiological efficacy.