Association Between Swimming Pool Operator Certification and Reduced Pool Chemistry Violations Nebraska,

Transcription

1 Association Between Swimming Pool Operator Certification and Reduced Pool Chemistry Violations Nebraska, Bryan F. Buss, DVM, MPH, DACVPM Nebraska Department of Health and Human Services OWCD, CDD, EIS Field Assignments Branch

2 Pool-Associated Outbreak Nebraska, December 2006 Chloramine toxicity State-licensed indoor, motel pool Untrained, uncertified operator 24 persons affected Ocular and respiratory illness 5 required medical care, 1 in ICU Pool inspected and closed

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4 Swimming in the United States Most popular children s recreational activity Second most popular activity for all ages >360 million recreational-water visits/year Increased numbers of recreationalwater associated outbreaks

5 Swimming Pool Water Chemistry Nebraska acceptable range Free chlorine (ppm) 2 10 ph Combined chlorine (chloramine) (ppm) 0.5

6 Swimming Pool Water Chemistry Nebraska acceptable range Outbreakassociated pool Free chlorine (ppm) ph Combined chlorine (chloramine) (ppm)

7 Chloramines Form when free chlorine reacts with sweat, urine, and other nitrogenous human wastes Remain in water or volatilize into air Can reach dangerous concentrations in enclosed space around indoor pools

8 Trichloramine or Nitrogen Trichloride (NCl 3 ) Increased development in this pool Compared with monochloramine (NH 2 Cl) and dichloramine (NHCL 2 ) More volatile More irritating Nitrogen Trichloride (NCl3) 3 ) Higher levels in low ph water Photo source:

9 National Pool Inspection Data Six U.S. Sites, 2002 Inspections n=22,131 Violations

10 National Pool Inspection Data Six U.S. Sites, 2002 Inspections n=22, % 1 violation Violations 8.3% pool closure

11 National Pool Inspection Data Six U.S. Sites, 2002 Inspections n=22, % 1 violation Violations n=21, % pool closure

12 National Pool Inspection Data Six U.S. Sites, 2002 Inspections n=22, % 1 violation Violations n=21, % nonmunicipal pools 8.3% pool closure

13 National Pool Inspection Data Six U.S. Sites, 2002 Inspections n=22, % 1 violation Violations n=21, % nonmunicipal pools 8.3% pool closure 38.7% water-chemistry

14 US Public Pool Operator Training 20 states required verifiable training for public pool operators (2006) Operators responsible for proper maintenance and operation of public pools minimal public health oversight In Nebraska, only 1 annual inspection per pool required Photo source: CDC Public Health Image Library

15 Objective Evaluate association between swimming pool operator certification and water chemistry violations in Nebraska

16 Study Design and Data Source Cross-sectional study Nebraska pool-inspection reports Routine inspection reports with free chlorine and ph values Start-up, follow-up, and complaint inspections excluded Combined chlorine values not available

17 Public Swimming Pool Classes Class A (municipal) and Regulations Trained, certified operators required onsite at all times Class B (nonmunicipal) Motel, hotel, apartment complexes, health clubs, and other privately-owned facilities Douglas County (Omaha metro area) and Lincoln require trained and certified operators Certification not required in all other counties

18 Number of Pools and Routine Class B operator certification requirement Inspections Number of pools by class Number of routine inspections by class A B All A B All Yes ,009 No ,001 Total ,417 2,010

19 Number of Pools and Routine Class B operator certification requirement Inspections Number of pools by class Number of routine inspections by class A B All A B All Yes ,009 No ,001 Total ,417 2,010

20 Number of Pools and Routine Class B operator certification requirement Inspections Number of pools by class Number of routine inspections by class A B All A B All Yes ,009 No ,001 Total ,417 2,010

21 Number of Pools and Routine Class B operator certification requirement Inspections Number of pools by class Number of routine inspections by class A B All A B All Yes ,009 No ,001 Total ,417 2, had 1 inspection; 680 >1 inspection median: 2; range: 1 7

22 Analysis of Free Chlorine Violations Violation defined as <2 ppm or >10 ppm Compared Class B (nonmunicipal) inspections Douglas County and Lincoln (certified operators are required) All other counties (certified operators not required)

23 Free Chlorine Violations Class B Pools, All Counties Certified operator required Free chlorine violation (<2 ppm or >10 ppm) Yes No No 167 (31%) Yes 138 (16%) ,112 1,417

24 Free Chlorine Violations Class B Pools, All Counties Prevalence ratio = 2.0 (95% CI, ) Certified operator required Free chlorine violation (<2 ppm or >10 ppm) Yes No No 167 (31%) Yes 138 (16%) ,112 1,417

25 Evaluation of ph Violations Calculated frequency of ph violations for Class B pools state-wide and by county Compared inspections from Douglas County and Lincoln pools Water quality reports available in these locations

26 ph Violations Among Statewide Class B Pool Inspections (n=1,417) Total ph violations N (%) Douglas and Sarpy Counties N (%) Other 91 counties N (%) 210 (14.8) 153 (72.9) 57 (27.1)

27 ph Violations Among Statewide Class B Pool Inspections (n=1,417) Total ph violations N (%) Douglas and Sarpy Counties N (%) Other 91 counties N (%) 210 (14.8) 153 (72.9) 57 (27.1)

28 ph Violations Among Statewide Class B Pool Inspections (n=1,417) Total ph violations N (%) Douglas and Sarpy Counties N (%) Other 91 counties N (%) 210 (14.8) 153 (72.9) 57 (27.1)

29 Water Quality Reports Douglas and Sarpy Counties (surface water) ph Alkalinity (ppm)

30 Water Quality Reports Douglas and Sarpy Counties (surface water) ph Alkalinity (ppm)

31 Water Quality Reports Douglas and Sarpy Counties (surface water) ph City of Lincoln (groundwater) Alkalinity (ppm)

32 Water Quality Reports Douglas and Sarpy Counties (surface water) City of Lincoln (groundwater) ph Alkalinity (ppm)

33 ph Violations in Douglas County and City of Lincoln Class B Pool Inspections Total (n=876) N (%) Douglas County* (n=580) N (%) City of Lincoln (n=226) N (%) 115 (13) 107 (93) 8 (7)

34 ph Violations in Douglas County and City of Lincoln Class B Pool Inspections Total (n=876) N (%) Douglas County* (n=580) N (%) City of Lincoln (n=226) N (%) 115 (13) 107 (93) 8 (7)

35 ph Violations in Douglas County and City of Lincoln Class B Pool Inspections Total (n=876) N (%) Douglas County* (n=580) N (%) City of Lincoln (n=226) N (%) 115 (13) 107 (93) 8 (7)

36 ph Violations in Douglas County and City of Lincoln Class B Pool Inspections Total (n=876) N (%) Douglas County* (n=580) N (%) City of Lincoln (n=226) N (%) 115 (13) 107 (93) 8 (7) *Majority of ph violations in Douglas County were low (<7.2), indicating over-correction by operators

37 Control of Source Water ph Variations Prevalence of ph violations affected by ph and alkalinity of source water entering pools Limited analyses of ph violations to inspections from two adjacent counties Bordered by Missouri River Share metropolitan utilities district Common river-water source Douglas County and selected Sarpy County cities Photo sources: (left); (right)

38 Analysis of ph Violations Violation defined as ph <7.2 or >7.8 Evaluated ph violations and concurrent ph and free chlorine violations Compared Class B inspections Douglas County (certified operators are required) Sarpy County locations (certified operators not required)

39 ph Violations Class B Pools Selected Locations Certified operator required Yes ph Violation (<7.2 or >7.8) No No 34 (27%) Yes 107 (19%)

40 ph Violations Class B Pools Selected Locations Prevalence ratio = 1.5 (95% CI, ) Certified operator required Yes ph Violation (<7.2 or >7.8) No No 34 (27%) Yes 107 (18%)

41 Chlorine and ph Violations Class B Pools Selected Locations Certified operator required Yes Both violations No No 16 (13%) Yes 36 (6%)

42 Chlorine and ph Violations Class B Pools Selected Locations Prevalence ratio = 2.0 (95% CI, ) Certified operator required Yes Both violations No No 16 (13%) Yes 36 (6%)

43 Analysis of Free Chlorine Violations by Pool Class Compared inspections from counties without Class B operator certification requirements Class B, nonmunicipal (certified operators not required) Class A, municipal (certified operators are required)

44 Free Chlorine Violations Counties without Class B Operator Certification Requirements Certified operator required No (Class B) Yes (municipal) Free chlorine violation Yes No 167 (31%) (13%) ,001

45 Free Chlorine Violations Counties without Class B Operator Certification Requirements Prevalence ratio = 2.4 (95% CI, ) Certified operator required No (Class B) Yes (municipal) Free chlorine violation Yes No 167 (31%) (13%) ,001

46 Analysis of ph Alone and Both ph and Free Chlorine Violations by Pool Class Compared inspections from selected Sarpy County locations Class B, nonmunicipal (certified operators not required) Class A, municipal (certified operators are required)

47 ph Violations Selected Sarpy County Locations Certified operator required Yes ph violation No No (Class B) Yes (municipal) 34 (27%) (7%)

48 ph Violations Selected Sarpy County Locations Prevalence ratio = 4.2 (95% CI, ) Certified operator required Yes ph violation No No (Class B) Yes (municipal) 34 (27%) (7%)

49 Concurrent Chlorine and ph Violations Selected Sarpy County Locations Certified operator required No (Class B) Yes (municipal) Both violations Yes No 16 (13%) (3%)

50 Concurrent Chlorine and ph Violations Selected Sarpy County Locations Prevalence ratio = 4.0 (95% CI, ) Certified operator required No (Class B) Yes (municipal) Both violations Yes No 16 (13%) (3%)

51 Multivariable Analysis Logistic regression demonstrated that crude prevalence ratios (PR) did not change substantially after accounting for frequency of inspection Data not shown Photo sources: www1.istockphoto.com (left); (center); (right)

52 Discussion Trained pool operators have critical role Mandatory operator training has potential to Improve swimming safety Enhance prevention of recreational water illness Routine analysis of pool inspection data useful for Public health decision making Evaluation of interventions

53 Discussion ph and alkalinity of source water entering pools affects operator s ability to manage ph Surface (river) water ph, alkalinity Challenge when pool operators attempt to lower and maintain ph Groundwater alkalinity, ph ~ 7.6 High alkalinity helps stabilize ph No or only slight ph adjustment required

54 Limitations Analyses based on certification requirements Multiple inspectors from 8 agencies Unable to account for differences among pools and operators

55 Conclusions Positive association between swimming pool operator training requirements and acceptable pool water chemistries Public pool management might be enhanced if operator training and certification are required

56 Recommendations Swimming pool industry Encourage training for all public pool operators Pursue training and maintain proficiency Regulatory agencies Consider requiring trained and certified operators for all public swimming pools

57 Acknowledgments Nebraska Department of Health and Human Services Tom Safranek Troy Huffman Sue Semerena Susan Farnsworth Jack Daniel Douglas County Health Department Tom Baker Doug Clark Lincoln-Lancaster County Health Department CDC Leon Marquart Michael Beach Anindya De Julie Magri Tom Török University of Nebraska-Lincoln Brett Foley The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention.

58 References Metropolitan Utilities District, Omaha, NE. Your 2005 water quality report. Available at: Metropolitan Utilities District, Omaha, NE. Your 2006 water quality report. Available at: Addy, K, Green, L, Herron E., ph and alkalinity. University of Rhode Island Cooperative Extension, Available at: Lincoln Water System, Lincoln, NE. Annual drinking water quality report for Available at: U.S. Bureau of the Census. Statistical abstract of the United States: th ed. Washington, DC: US Bureau of the Census, 1995.

59 References CDC. Surveillance data from swimming pool inspections selected states and counties, United States, May September MMWR 2003;52: Dziuban EJ, Liang JL, Craun GF, Hill V, Yu PA, Painter J, et al. Surveillance for waterborne disease and outbreaks associated with recreational water United States, MMWR Surveill Summ Dec 22;55(12):1-30. Nebraska Health and Human Services, Regulation and Licensure. Operation and management of public swimming pools, 178 NAC 2 (June 8, 2004). Available at: Lachocki TM. Pool and spa operator training a smart choice. The Official Newsletter of the NSPF. 2006;41(4):5, Available at:

60 Swimming Pool Water Chemistry Nebraska acceptable range Outbreakassociated pool Free chlorine (ppm) ph Combined chlorine (chloramine) (ppm)

61 National Pool Inspection Data Six U.S. Sites, ,131 Pool Inspections 45.9% (10,158) No violations 54.1% (11,973) 1 violation 8.3% (1,837 of 22,131) Immediate Pool Closure

62 National Pool Inspection Data Six U.S. Sites, ,561 Total Violations 38.7% Water- Chemistry 38.6% Filtration and Recirculation System 22.7% Policy and Management 95.5% of all violations Nonmunicipal Pools 4.5% Municipal Pools

63 National Pool Inspection Data Six U.S. Sites, 2002 Inspections n=22, % 1 violation Violations n=21, % nonmunicipal pools 8.3% pool closure 38.7% water-chemistry

64 Number of Pools and Routine Class B operator certification requirement Inspections Number of pools by class Number of routine inspections by class A B All A B All Yes ,009 No ,001 Total ,417 2, had 1 inspection; 680 >1 inspection median: 2; range: 1 7

65 Calculation of Prevalence Ratio as Measure of Association Prevalence ratio = Prevalence in exposed Prevalence in unexposed Outcome + - = A/A+B C/C+D Exposed A B A + B Not exposed C D C + D A + C B + D Total

66 ph Violations Among Statewide Class B Pool Inspections (n=1,417) Total ph violations N (%) Douglas and Sarpy Counties N (%) Other 91 counties N (%) 210 (14.8) 153 (72.9) 57 (27.1)

67 Water Quality Reports Douglas and Sarpy Counties (surface water) City of Lincoln (groundwater) ph Alkalinity (ppm)

68 ph Violations in Douglas County and City of Lincoln Class B Pool Inspections Total (n=876) N (%) Douglas County* (n=580) N (%) City of Lincoln (n=226) N (%) 115 (13) 107 (93) 8 (7) *Majority of ph violations in Douglas County were low (<7.2), indicating over-correction by operators