Legionella bacteria can colonise and proliferate in water systems in the built environment and can be spread by aerosol generation. If inhaled by a susceptible individual, this can lead to respiratory infections such as Legionnaires’ Disease (LD), or the generally milder Pontiac fever. Evaporative cooling systems (ECS), including cooling towers, used in industrial processes to dissipate excessive heat are prone to contamination by Legionella. From these systems it is possible for contaminated aerosols to be dispersed over a wide area, potentially exposing workers on site, neighbouring workplaces or nearby members of the public. Analysis of reported data on outbreaks of LD in Great Britain, collated for a ten year period, identified 44 separate legionellosis outbreaks of which seven were attributed to ECS and were responsible for 229 infections and 10 fatalities. This prompted an examination of health and safety inspection records which revealed, over a five year period, 321 enforcement actions taken against failings in Legionella control, of which 31% were attributed to cooling towers. Based on this evidence, an intervention programme was undertaken by health and safety inspectors in which 1,906 sites with ECS were inspected. During these inspections, sites were rated against four topics that are used to demonstrate compliance with statutory requirements for Legionella control: Risk Assessment; Written Control Scheme; Implementation of Control Scheme; and Record Keeping. While there was compliance at the majority of sites, breaches of the legislation were found at 625 sites (33% of those inspected), leading to 409 Improvement Notices (compelling dutyholders to make improvements to health and safety breaches of law in a given timeframe) and 12 Prohibition Notices (compelling dutyholders to stop work until they have remedied breaches in health and safety law) being served at 229 sites (12.0% of those inspected).

Data from the intervention programme was analysed to identify root causes of these breaches of legislation on Legionella control. The majority of Improvement Notices (53%) were issued for the ‘lack of effective implementation of a Written Control Scheme’, with ‘Risk Assessment’ and ‘Written Control Scheme’ both accounting for 23%. More detailed examination showed major problems to be lack of training; failure to maintain the cleanliness of cooling towers and the water within them; risk assessments either being absent or not up to date, i.e., no longer representing the risks present; and Written Control Schemes being absent or insufficiently detailed.

This provides a valuable data resource for dutyholders, so that they can understand where they need to focus to achieve significant improvement in legal compliance and therefore reduce the risk of LD for employees and members of the public affected by their workplace, and valuable data for regulators to target future interventions aimed at improving dutyholder compliance leading to better protection of workers and members of the public.

军团菌细菌可以在建筑环境中的水系统中定居和繁殖，并可以通过气溶胶产生而传播。如果被易感个体吸入，则可能导致呼吸道感染，例如退伍军人病（LD）或一般较轻的庞蒂亚克热。蒸发冷却系统（ECS），包括冷却塔，用于工业过程中以散发过多的热量，容易受到军团菌的污染。从这些系统中，被污染的气溶胶有可能散布在广阔的区域中，从而有可能使现场，邻近工作场所或附近公众中的工人暴露。对报告的有关英国LD暴发的数据进行的分析（整理了十年），确定了44例单独的军团菌病暴发，其中7例归因于ECS，造成229例感染和10例死亡。这促使对健康和安全检查记录进行检查，该记录显示在五年的时间内对军团菌的失败采取了321项执法措施。控制，其中31％归因于冷却塔。基于这些证据，健康和安全检查员实施了一项干预计划，其中对1,906个带有ECS的场所进行了检查。在这些检查期间，根据四个主题对站点进行了评级，这些主题用于证明符合军团菌的法定要求控制：风险评估；书面控制计划；实施控制方案；和记录保存。尽管大多数站点都遵守法规，但发现有625个站点违反了法律（占被检查站点的33％），从而导致409项改进通知（迫使工作负责人在给定的时间范围内改进健康和安全方面的违法行为）在229个地点（占被检查者的12.0％）发送了12份禁止通知书（迫使工作人员停止工作，直到他们纠正了违反健康与安全法的行为）。

分析了干预计划中的数据，以找出违反军团菌控制法规的根本原因。大部分改进通知（53％）是由于“缺乏有效实施书面控制计划”而发出的，“风险评估”和“书面控制计划”均占23％。更详细的检查表明，主要问题是缺乏培训；无法保持冷却塔及其内部水的清洁度；缺少或未更新的风险评估，即不再代表存在的风险；书面控制方案不存在或不够详细。

这为当值负责人提供了宝贵的数据资源，使他们可以了解需要集中精力以实现法律合规性的显着改善，从而为受工作场所影响的员工和公众降低违约风险，并为监管机构提供有价值的数据。针对未来的干预措施，以改善责任人的合规性，从而更好地保护工人和公众。