Once we've completed a risk assessment, we have extensive documentation about the potential harm that a Hazard can cause to human health. But in public health, we can't simply stop there and call our work done. If we've identified an unacceptable health risk, we need to do something about it and that brings us into the realm of risk management. Risk management is basically the adoption of steps to either eliminate risk or lower that risk to some acceptable level. And I need to acknowledge right up front that that acceptable level is going to be a political compromise. It is very rarely based only on health input and instead includes other economic and ethical and additional inputs. If we think about what risk management could look like, it has many forms. It could involve doing nothing at all. It could involve regulations to control the production and use in disposal of certain hazards, it could involve licensing and registration laws. It might involve standard-setting laws that establish certain allowable exposure levels. It could focus on control oriented measures that require the reduction of that hazard through changes to for example a workplace that's emitting pollution. It could involve information programs to educate people who are exposed. It could also involve monitoring to allow for regulatory enforcement. I will say in most cases, it's actually going to involve some sweet of these different options. Let's hike back to the hierarchy of controls which we talked about in previous modules. This hierarchy gives us potential risk management approaches and also prioritizes them in terms of the order we should try them in, in order to ensure that we tried the most effective approaches first and the least effective last. If we think about the hierarchy of controls right at the top, what we should try first is elimination. We want to physically remove the hazard wherever possible, we would then try substitution replacing one hazard with one that's slightly less harmful or perhaps substantially less harmful. The third approach would be engineering controls, again, isolating people from the hazard. The fourth would be administrative controls changing people's behavior around that hazard, and the fifth would be personal protective equipment trying to put a personal barrier between that person and the hazard around through equipment that they wear. There are seven steps of risk management. The first is to identify the future problem or event that we want to avoid. The second is to formulate the actual problem we're trying to prevent. The third is to identify and defined objectives. The fourth is for us to identify and evaluate what risk management options are available. The fifth is to actually make our risk management decision considering a lot of different factors that we'll talk about in a moment. The sixth is implementing the decision and the seventh is monitoring environmental and public health changes that result from our risk management activities. Let's look at the interface between three critical aspects here, risk assessment, risk management, and the evaluation of our risk management. So if we look at the upper left-hand circle here, this should look familiar from our risk assessment module. So here we see the three key steps of risk assessment hazard identification, dose-response and exposure assessment and we see that those feed into risk characterization. Risk characterization then overlaps with our risk management circle on the right here, and so we can see that our risk characterization is one bit of input into risk management decisions. We also need to consider other public health considerations, legal and statutory obligations against societal and economic factors, and politics which are unavoidable. Once we implement a risk management approach then we move into the evaluation circle in the lower left corner. So here we need to evaluate the cost and effectiveness of our approaches. We need to identify different options and we want to characterize our sources. So we can see that all three of these circles do overlap and they interface with one another. I also want to highlight that there's another element here risk communication that we absolutely need to consider. So risk communication is a key element of both assessing but also controlling risk, and it requires two way communications and engagement with affected populations. The idea behind risk communication is that it allows populations to make informed decisions to protect themselves and their loved ones from this risk. So the goals of risk communication are to share information, to allow people to protect their health and minimize harm. Ideally to allow them and encourage them to change behavior, to enable a dialogue between those exposed and policy makers and perhaps those creating the exposure. And improve relationships and trust and the absolutely to involve stakeholders in our decision-making process. So the figure here shows the intimate interplay between risk assessment and risk management and risk communication acknowledging that risk assessment is very much science base. Risk management is policy-based and risk communication involves exchanging information about both of those aspects. Let me walk you through an example here for a specific environmental hazard nanoparticles. We've talked in other modules about how these are an emerging environmental health threat. We've also previously examined different exposure pathways and routes, but let's summarize and look at the interaction between risk assessment and risk management. The upper left-hand circle in this figure should look familiar, this is our first step of risk assessment hazard identification. So we look at available for example experimental animal studies and human data. That leads us to our exposure or dose response data. So we may look at again in vitro or in Vivo studies to assess the relationship between dose and subsequent response. The upper middle circle is exposure assessment. So here we're determining what population is exposed, when and to how much of this Hazard. The lower right-hand circle is risk characterization again, where we wrap up the information from our dose-response and from our exposure assessment and consider things like susceptible and vulnerable populations. And then the upper right-hand circle here is risk management. So here is where we consider the health risk that we identified in context with public health information, legal and societal obligations and opinions, economic factors and things like that. And all of those things are going to influence our decision as to how to manage this particular risk. I'd like to mention a few risk management tools that we have available to us that allow us to evaluate environmental health policies designed to manage risks. We could do a couple things one. We could look at trends in compliance in hazards that are emitted by polluters. For example, what our air and water concentrations around polluting facilities, a sub metric here might be what fraction of those facilities have actually implemented the hazard controls that they're required to implement. Ideally, we'd like to see that at 100%, but we certainly want to know if it's less than 100%. We could also look at trends in compliance among exposed humans, so we could measure people's ambient exposures or we could measure their dose via biomarkers and biomonitoring. Or third, we could evaluate the amount of this particular hazard that's being produced or generated. We could go to manufacturing records for that or other models that might allow us to estimate total emissions. So as I said earlier in public health, it's not sufficient just to document a hazard. What we don't want to have happen is our risk assessment documentation get filed away on a shelf somewhere and never acted on. If we find an unacceptable risk we absolutely must act on that. We have a moral and ethical and legal obligation to do so. Risk management gives us a way to organize our thoughts about how to actually go in and eliminate or reduce the hazard to an acceptable level. Promoting public health and always keeping an eye out for environmental justice issues that may need special attention.
