Association between swimming pool operator certification and reduced pool chemistry violations Nebraska, 2005-2006

Journal of Environmental Health, April, 2009 by Bryan F. Buss, Thomas J. Safranek, Julie M. Magri, Thomas J. Torok, Michael J. Beach, Brett P. Foley

Comparing only Douglas County and Sarpy County inspection reports from nonmunicipal, Class B pools with the shared surface water source, pH violations were more likely in Sarpy County (27.0%, 34 of 126) than in Douglas County (18.4%, 107 of 580) where operator certification is required (PR = 1.5, 95% CI = 1.05-2.04). Inspections in Sarpy County (12.7%, 16 of 126) were also more likely than those in Douglas County (6.2%, 36 of 580) to have concurrent pH and free chlorine violations (PR = 2.0, 95% CI = 1.2-3.6). Comparing inspections from Class B pools with those from Class A pools in only Sarpy County locations, Class B pools were more likely (27.0%, 34 of 126) than Class A (6.5%, 2 of 31) to have a pH violation (PR = 4.2, 95% CI = 1.1-16.5) and also were more likely (12.7%, 16 of 126) than Class A (3.2%, 1 of 31) to have concurrent pH and free chlorine violations (PR = 4.0, 95% CI = 0.5-28.6). Adjusted odds ratios calculated by multivariable analysis to control for frequency of inspection demonstrated minimal change from the corresponding crude prevalence ratios (Table 2).

TABLE 2
Crude Prevalence Ratios Compared to Corresponding Simple
and Adjusted Odds Ratios

Measure of                   Inspection Violation Comparisons
Association

                              Class B Only--Pools without vs.
                           Pools with Certification Requirements

                      Free Chlorine          pH (a)            Both
                                                          Violations (a)

Crude PR (b)               2.0                1.5               2.0

OR (c) (95% Cl)  2.39 (1.85-3.09)    1.63(1.05-2.55)  2.20 (1.18-4.10)
aOR (d) (95%Cl)  2.35 (1.79-3.09)    1.66 (e)         2.19 (1.12-4.27)
                                     (1.00 (f)-2.77)

Measure of          Inspection Violation Comparisons
Association

                    Class B Pools vs. Class A Pools

                    Free Chlorine       pH (a)   Both Violations (a)

Crude PR (b)        2.4             4.2             4.0 (e)

OR (c) (95% Cl)   2.98              5.36            4.37 (e)
                 (2.15-4.13)       (1.21-23.68)  (0.56-34.48)

aOR (d) (95%Cl)   2.90                 5.26         4.33 (e)
                 (2.08-4.08)       (1.08-25.64)  (0.52-35.71)

 (a) All pH comparisons restricted to inspections from selected
locations as described by methods.
(b) Crude prevalence ratios (PR) represent results presented in text
with 95% confidence intervals.
(c) Simple odds ratios (OR) calculated without controlling for
frequency of inspection.
(d) Adjusted odds ratios (aOR) calculated using logistic regression to
control for inspection frequency.
(e) Value not statistically significant.
(f) Rounded to 1.00; actual value, 0.998.

Discussion

This evaluation demonstrates potential benefits of mandatory training and certification for public swimming pool operators. As indicators of pool mismanagement, water chemistry violations of both pH and free chlorine are more common among nonmunicipal, Class B pools in Nebraska counties that are not required to have trained and certified operators. These results underscore the critical role that trained pool operators have and emphasize the potential that operator training has to improve swimming safety and enhance prevention of recreational water illness (Dziuban et al., 2006). Furthermore, this evaluation illustrates that routine analysis of pool inspection data is useful for public health decision making and evaluation of effects of future interventions (CDC, 2003).