Public Health Surveillance, Public Communication and Participation
Lesley V. D’Anglada
The role of public health authorities is to protect, assess and ensure the health of people and communities. These agencies also play a role in promoting healthy environments, thus reducing the toll from illness due to exposure to pathogens or harmful substances such as cyanotoxins in drinking and recreational waters, in food or in water used for dialysis. Legal authority and regulations facilitate the control and management of blooms as well as public health responses and risk communication when they do occur.
The role of the responsible authority is likely to focus on surveillance, including independent verification of water quality and ideally, assessment that Water Safety Plans (WSPs) are being implemented effectively, rather than the day-to-day on-site management and monitoring. Operators of drinking- water supplies and managers of recreational sites or occupational water use are required for the day-to-day management (and assessment) of risks, including those from cyanotoxins. However, the role of authorities may be broader where regulations are sparse, water quality requirements such as limits for cyanotoxin concentrations have not been defined, institutional capacity is limited or the surveillance of water-use systems is challenging because of their high number, geographic spread or remoteness. Such situations may require an active role of public authorities in management, for example, in the development of WSPs (see Chapter 6). This chapter focuses on the role of public authorities in surveillance, the development and implementation of Incident Response Plans (IRPs) as well as in communicating risks to the public.
The WHO Framework for safe drinking-water outlines the key steps in providing safe drinking-water (Figure 15.1; see also the Guidelines for Drinking-Water Quality (WHO, 2017), Chapter 1), and these key steps can also be applied to safe design, operation and management of recreational or occupational water-use sites. Within this framework, public authorities have a role particularly at the “front end”, that is, in setting targets, and at the “back end”, that is, in surveillance. The authorities responsible for both may be different, operating on different levels: while setting targets often occurs on the national level by legislation, surveillance is typically local, requiring good knowledge of the local conditions and challenges.
Setting cyanotoxin water quality targets or action thresholds can be based on the guideline values summarised in Chapter 5 (see also Chapter 2 for their derivation), with the guideline values for short-term exposure through drinking-water being particularly relevant during bloom events. How the guideline values for lifetime exposure “translate” into targets for waterbody management is discussed in Chapters 6 and 7. In an event of a cyanotoxins incident, it is important to consider the risks from exposure to cyanotoxins
Figure 15.1 Framework for safe drinking-water (from the WHO Guidelines for Drinking- water Quality; WHO, 2017).
in relation to health risks from other microorganisms and chemicals (see section 5.1 and Chapter 6 for a discussion on target setting).
Aspects of Surveillance
The other key role of public authorities, that is, surveillance, is often perceived to focus on assessing whether water quality meets the targets defined for a given parameter, such as cyanobacterial biomass or cyano- toxin concentrations. However, for drinking-water supply, surveillance is much more effective if it also includes a critical review of the facilities, their surroundings and operation, including operational parameters. This is best done through inspections of the site, review of records of operational parameters and conversations with operating staff. If management plans such as WSPs (see Chapter 6) and IRPs (see below) are in place, this greatly facilitates surveillance and provides a useful basis for discussions on potential improvement with operators and managers. This also applies to small supplies and situations with limited resources, where WSP development can be particularly useful (for more information, see WHO, 2012). As small supplies are typically less complex, system description, hazard analysis and risk assessment tend to be more straightforward and more readily accomplished even with a lower level of expertise, for example, by using a sanitary inspection as basis for the WSP. Outcomes may be highly valuable, allowing the water authority to prioritise its activities. For drinking-water supplies as well as for recreational sites or workplaces, surveillance should start with site inspections to assess the risk of cyanobacterial blooms, based on historical events and environmental conditions that lead to cyanobacterial bloom formation. Surveillance therefore requires an understanding of the systems - from catchment to the point of use and possible human exposure. The guidance given in Chapters 5-10 presents the necessary background, both for operators and for authorities performing surveillance, on assessing and managing risks of cyanobacterial blooms.
Through surveillance, public authorities gather a wide overview of conditions causing blooms and thus develop a locally and regionally specific understanding of the water systems. This enables them to effectively advise operators of drinking-water supplies and managers of recreational sites or workplaces on measures that have proven effective in similar cases. The operator of a drinking-water supply or manager of a recreational site is responsible for identifying hazards, assessing risks and identifying as well as implementing control measures, including organising collaboration with other public authorities and agencies. However, particularly in small-scale situations with limited resources, the role of public authorities can also involve triggering networking and exchange of experience between operators as well as organising collaboration.
Across the globe, different authorities may be responsible for responding to cyanotoxin occurrence, and responsibility may also be shared between environmental and health authorities. For managing cyanobacteria and cyanotoxins, contact and exchange are particularly important between health and environmental authorities, but in some cases also with those responsible for allocating water to specific uses and managing flow regimes (in some countries termed “water boards”). This is a basis for developing management strategies that address the problem at its source: that is, the causes for cyanobacterial proliferation and bloom formation.
To ensure appropriate responses to cyanobacterial bloom incidents, close coordination with all partners, including environmental authorities, is particularly critical so that those with responsibilities for specific incidence response actions are prepared to react quickly when contacted during the incident, to restore drinking-water service. IRPs help in providing the tools needed for an effective response and the protection of public health during a cyanobacterial bloom. Each cyanotoxin event is different, and correspondingly, the characteristics of the area, available resources, the interaction with outside partners and the response will be specific to the situation.