ATP as a Marker for Surface Contamination of Biological Origin in Schools and as a Potential Approach to the Measurement of Cleaning Effectiveness

Abstract

To address the need for a quantitative approach to the measurement of cleaning effectiveness, related to biologically derived surface contamination, three commercially available adenosine triphosphate (ATP) test systems were used to collect multiple samples measured in relative light units (RLUs) from 27 elementary schools in the southwestern United States before and after a standardized cleaning protocol. The database consisted of 6480 ATP measurements from four critical surfaces (student desktops, cafeteria tabletops, and restroom sinks and stall doors). Data was assessed according to ranges of ATP values before and after cleaning. Results showed the potential for such data to provide the basis for a standardized approach to the measurement of cleaning effectiveness, based on detection and quantification of pollutant loads of biological origin, across critical surfaces in school building environments. It is anticipated that verification of this data in school buildings across different geographic and climatic regions will lead to the establishment of "acceptable" ranges of ATP values that can be used as a practice-based approach to improving cleaning practices and contributing to healthier school environments.

Building and indoor environmental quality assessment of Nigerian primary schools: A pilot study

“…The pre‐cleaning ATP values were comparable to data from elementary schools in southwestern United States, reporting the trimmed mean log‐transformed value of 5.01 (ie, 102, 300 RLUs) and suggesting reasonable range ≤5.37 (ie, 234, 400 RLUs). Based on our results, three out of 5 schools were above 234, 400 RLUs.…”

“…The pre-cleaning ATP values were comparable to data from elementary schools in southwestern United States, 50 reporting the trimmed mean log-transformed value of 5.01 (ie, 102, 300 RLUs) and…”

“…The template was disinfected with 95% isopropyl alcohol before each use. After pre‐cleaning sampling, the desks were cleaned according to the protocol described by Shaughnessy et al as follows: (a) test surfaces were first wiped with a clean microfiber towel and wiped with disinfectant, and (b) the surface was then wiped with another clean microfiber cloth until dry. Finally, post‐cleaning ATP samples were collected directly adjacent to locations where the corresponding pre‐cleaning samples were taken.…”

“…The routine cleaning protocol based on visual assessment appears inadequate for the removal of the unseen fraction. A study by Shaughnessy et al described a quantitative approach to measure cleanliness in schools using adenosine triphosphate (ATP) as a marker for surface contamination. Another study associated cleanliness of high contact surfaces (such as desks and cafeteria tables) with students' health outcomes …”

An assessment of indoor environmental quality in schools and its association with health and performance

“…Whereas the results from different ATP systems were significantly correlated both before and after the cleaning, the results using RODAC were correlated with only pre-cleaning ATP. More detailed analysis of ATP and RODAC data for assessment of cleaning effectiveness have been reported elsewhere [17]. In this study, the results from using one ATP system NovaLUM (Charm Sciences, Inc., Lawrence, Kans.)…”