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HBI FEDECAI Conference Legionella – A British Perspective Presented by David Handley of Healthy Buildings International On 24th October 2002 in Valencia
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HBI What is Legionnaires’ Disease ? Potentially fatal form of pneumonia Affects anybody, but some individuals are particularly susceptible Contracted by inhalation of legionella bacteria from contaminated water High fever, chills, headache & muscular pain 200 –250 reported cases each year Fatal in approximately 12% of cases Legionellosis – range of illnesses cased by legionella bacteria
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HBI What are Legionella? Types of bacteria Found in water at temperatures 6°C to 55°C Requires nutrients to multiply 40 different types of legionella Legionella pneumophila – 16 serogroups Legionella pneumophila sg1 is the causative bacterium for 90% of Legionnaires’ Disease
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HBI Where are legionella found? Found in environmental water sources Colonises manufactured water systems Cooling towers Hot and cold water systems Air handling plant Other plant that uses or stores water
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HBI History of Legionnaires’ Disease 1976 Philadelphia »Clinical samples pre 1930 1985 Staffordshire Hospital 1986 BBC London 2002 Barrow-in Furness
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HBI Legionella - Legislation Health and Safety at Work Act 1988 The Control of Substances Hazardous to Health 1994 (COSHH) Approved Code of Practice (ACoP L8) »Launched 8th January 2001 »Replaced HS(G) 70, ACoP L8 (Rev) & MISC 150
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HBI Requirements of the ACoP Identify & Assess Sources of Risk Prepare a Scheme for Preventing or Controlling the Risk Implement & Manage the Precautions Keep Records of the Precautions Implemented Appoint a Person to be Managerially Responsible
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HBI Changes in the New ACoP (1) A New Title »Legionnaires’ Disease, The Control of Legionella Bacteria in Water Systems Previously »The prevention or control of legionellosis (including legionnaires’ disease) Aim »to directly identify the subject matter and avoid confusion
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HBI Changes in the New ACoP (2) The New ACoP is Split (Part 1 and Part 2) »Part 1 – The ACoP »Part 2 – Guidance on Control Includes Guidance in Part 1 Aim »to make clear the Employers duty under the COSHH Regs to control legionella
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HBI Changes in the New ACoP (3) Use of Risk Systems HAS TO BE AVOIDED in so far as is reasonably practicable »Previously SHOULD BE »Must assess practicality of removal of risk system Now requires that you CONTROL the Risk »Previously MINIMISE the Risk
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HBI Changes in the New ACoP (4) Now has a requirement to have access to competent help when conducting a risk assessment Code of Conduct for organisations providing water treatment services »Water Management Society »British Association of Chemical Specialities
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HBI Changes in the New ACoP (5) Greatly expanded section on Managing the Risk - gives advice on competence & training for those: »Developing, managing & conducting the risk assessment »Implementing controls »Managing external Contractors Including detailed lines of communication
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HBI Changes in the New ACoP (6) Emphasises the duty of suppliers of products and services to : »Carry out work effectively »Liase with Duty Holders about deficiencies »Clearly define limitations of work undertaken »Ensure staff have necessary ability, training, information, resources etc. Code of Conduct
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HBI Design Requirements Design requirements of L8 »Ensure that risk is reasonably avoided or, where not reasonably practicable; »Ensure that the plant or water system is so designed as to be safe and without risk when used »Provide on handover information as to safe usage. Such information should be updated as applicable.
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HBI Changes in the Part 2 Guidance (1) Cooling Towers Much greater detail on regimes of control Routine quarterly testing of cooling towers for the presence of Lp (records kept for 5 yrs) Table 1 – details weekly, monthly & quarterly tests for make-up water and cooling water Action levels for Lp & aerobic bacterial counts outlined in Table 2
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HBI Part 2 Guidance Cooling Towers Must have regular programme of visual inspection Particular attention is paid to: »Tower Pack
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HBI
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Part 2 Guidance Cooling Towers Must have regular programme of visual inspection Particular attention is paid to: »Tower Pack »Drift Reducers
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HBI
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Part 2 Guidance Cooling Towers Must have a programme of water treatment effective against: »Corrosion »Scale formation »Fouling »Microbiological Activity
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HBI Part 2 Guidance (2) Cooling Towers Weekly »Conductivity »Oxidising Biocide Reserve »pH »Microbiological Activity (Dip Slide)
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HBI Changes in the Part 2 Guidance
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HBI Part 2 Guidance (2) Cooling Towers Monthly »Hardness - Ca, Mg & Total !! »Oxidising Biocide Reserve »pH »Microbiological Activity (Dip Slide) »Chloride »Inhibitor Treatment Level »Concentration Factor
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HBI Part 2 Guidance (2) Cooling Towers Quarterly »Legionella »Total Alkalinity & Sulphate »Suspended Solids »Soluble & Total Iron »Temperature
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HBI Part 2 Guidance (2) Cooling Towers Cleaning & Disinfection »Before tower first commissioned »After shutdown of more than one month »If any mechanical work undertaken »If cleanliness is in doubt »If microbial test results show a problem »Temperature »Every six months
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HBI Microbial Monitoring – Action Levels Aerobic Count at 30°C (cfu/ml) Legionella Bacteria (cfu/l) Action 10,000 or less100 or lessSystem under control >10,000 and up to 100,000 >100 and up to 1,000 Review Programme >100,000More than 1,000Corrective Action
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HBI Changes in the Part 2 Guidance (2) Domestic Hot & Cold Water Systems Removal of the limit of 300 litres for DHW TMVs given recognition and procedures outlined Table 3 & Checklist 2 introduced as guides to monitoring Sentinel outlets introduced Temperature measurement on DHW return Annual tap temps reduced to “representative”
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HBI Changes in the Part 2 Guidance
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HBI Changes in the Part 2 Guidance (3) Showers Now included!! Procedures outlined for showers served by TMVs (include hot supply as sentinel outlet) Checklist 2 gives guide to monitoring Shower heads – quarterly or as necessary Flush little-used outlets weekly
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HBI Changes in the Part 2 Guidance (4) Other Risk Systems Checklist 3 includes: »Water misting systems »Air washers & wet scrubbers »Dental equipment »Car/bus washes »Fountains & water features »Etc.
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HBI Part 2 Guidance Hot & Cold Water Systems Monthly »Calorifier Temperatures – Flow & Return »Sentinel Taps (Nominal Nearest & Furthest) »Supplies to Thermostatic Mixing Valves
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HBI Part 2 Guidance Hot & Cold Water Systems Annual »All Monthly Tests »Representative Number of Hot Water Outlets
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HBI Part 2 Guidance – Control Limits Hot & Cold Water Systems Calorifier Temperatures »Flow >60°C & Return <50°C Taps »Hot >50°C within 1 minute »Cold <20°C after 2 mins Supplies to Thermostatic Mixing Valves »Same as Taps
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HBI Legionella Monitoring – Action Levels Legionella Bacteria (cfu/l) Action 100 or lessSystem under control >100 and up to 1,000Review Programme More than 1,000Corrective Action
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HBI Legionella Risk Assessment Risk at Source »Condition »Accessibility Cultivation Conditions »Temp & pH »Microbe Count & Water Change Rate Exposure »Period and Type »Exposed Population
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HBI Precautions & Control Scheme Prepare a Suitable System of Control Manual »Details Written Scheme Regime of Maintenance & Control Responsible Persons Reporting Procedures Risk Assessments
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HBI Lp High Risk Systems Cooling Towers »Diligent Water Treatment Programme »Quarterly Lp Testing »Once or Twice Weekly Water Treatment Tests Showers »Minimum Quarterly Clean/Descale of Shower Head »Weekly Flush Through of Low Usage Systems »Annual Lp Testing
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HBI Implement & Manage the Precautions Log Book »Water Treatment Results » Lp Tests » Temperature Measurements »Cleanliness of systems »Disinfection certificates etc
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HBI Record Keeping Keep Records »Manual (incl. Risk Assessments) 2 Years »Log Book Records 5 Years
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HBI Responsible Person Manage the Control Scheme Training Regular Reviews Communication
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HBI The Barrow Outbreak (1) Britain’s Biggest Ever Outbreak of LD »131 confirmed cases »Trawl of GPs nationwide shows 10 more suspected cases »41 people still in hospital – 8 in intensive care »Majority of victims aged 55-75 - none <15yrs old »4 Fatalities - 3 Women, 1 Man – all >50 yrs old »Mortality Rate 3.1%. Lower than norm - due to rapid diagnosis & more effective antibiotics
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HBI The Barrow Outbreak (2) Identifying the Source »Epidemiological link to centre of Barrow-in- Furness »HSE checked 132 locations in immediate area »Most rapidly eliminated – just 4 cooling towers »3 proved negative for legionella spp »Causative organism identified as Legionella pneumophila serogroup 1 – subtype Benidorm »Strain isolated from some patients and the Forum 28 Arts Centre cooling tower
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HBI The Barrow Outbreak The Forum 28 Arts Centre
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HBI The Barrow Outbreak
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HBI The Barrow Outbreak (3) The Arts Centre Cooling System »30 yrs old and in poor condition »Local Council responsible for site maintenance »Biocide dosing system malfunctioning? »Discharging “discoloured steam” into alleyway »Part of system not used, but not decommissioned »6-monthly disinfection being done for free! »System believed to have been operating badly for some time
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HBI The Barrow Outbreak
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HBI The Barrow Outbreak (4) Action Being Taken »Technical Manager of Local Council has been suspended on full pay “to minimise contact” »A meeting has been held between affected people and firm of solicitors »Cumbria Police have 20 Officers investigating the deaths »Maintenance Records have been seized »Police investigations include “negligence, recklessness and corporate manslaughter”
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