The California drought is now in its fifth year, but we still know little about how it has affected public health.
A half-million acres of farmland were fallowed in 2015, leaving thousands of agricultural workers jobless. More than a thousand families saw their drinking water wells go dry. Many more were forced to ration water, either because their well production slowed down, or because a local agency imposed rationing. Many lakes and ponds are experiencing toxic algae blooms, which can lead to sickness in people and pets.
The drought has consequences for human health, both physical and emotional. One study in Tulare County recently attempted to quantify these effects via door-to-door polling. This was one survey in two small communities.
Now Kurt Schwabe at the University of California Riverside plans a statewide study to assess the drought’s effect on human health. Schwabe, a professor of environmental economics and policy, has been awarded a $284,000 grant from the Robert Wood Johnson Foundation to conduct the study. It will involve a detailed analysis of data already collected on public health, which will be correlated with weather data to determine the drought’s influence.
Water Deeply recently spoke with Schwabe to learn more about this project and what he hopes it will lead to.
Water Deeply: What prompted your interest in studying the links between drought and health?
Kurt Schwabe: The genesis of this was that you hear a lot of what seem to be large numbers in terms of the impacts of drought – that it resulted, say, in agricultural losses around $2.7 billion and 10,000 seasonal jobs in 2015. At first glance people think, well, that’s a pretty big number. And it is.
But if you put it in relative terms, that’s about 5 percent of agriculture’s annual value, and agriculture is about 3 percent of the state’s GDP. Multiply those numbers together and you get about a 0.15 percent impact on the state in terms of overall economic productivity. And you start saying, maybe the drought doesn’t seem like it’s been so devastating in relative terms to California’s economy. So my feeling is, the median and aggregate tell part of the story, but not the whole story.
So what we want to talk about are what we call the equity or distributional impacts of the drought. While some people may not be impacted very much, for some communities the impact may be quite significant, not only in the short run, but potentially long-run.
And that’s where the health impacts come in. Then, when you start adding up those costs, they can really tip the scales as to whether there is justification for a change in policy.
Water Deeply: Is this an ‘out of sight, out of mind’ sort of crisis?
Schwabe: There’s quite a bit of information on what the short-run impacts are of drought on agriculture – things like lost jobs and reduced [crop] yields. You also see a significant amount of evidence in terms of impacts of drought on fish survival rates. And more recently, you start to hear about the potential impacts on urban water usage. Those are certainly three understandable categories to look at.
But the real effects on livelihood are about health and wellbeing. You just don’t see that evidence being presented to policymakers. It’s not necessarily that they don’t think about it. It’s that they may not have been presented with the evidence of the impacts so it can be used effectively in their decision-making.
Water Deeply: Which resources are you using for this study?
Schwabe: Essentially we’ll be looking at putting together and merging a couple of different datasets. They come from the California Office of Statewide Health Planning and Development, and there’s another we’ll use which collects data from what’s called the California Health Interview Surveys.
There will be several different weather indicators we’ll use to look at the impact of adverse weather events. There’s going to be plenty of data on different measures of weather. Hot weather today also might have a delayed effect. So not only are we going to use different climate measures, but we’ll look at them over different time horizons. It’s a puzzle in that sense.
We’re going to be looking at, how do adverse weather events affect those two datasets over the entire state, all 58 counties?
Water Deeply: Does the data cover the current drought period?
Schwabe: We’ll try to get the most recent drought. I think we can get the data through 2014. With one of the datasets, we’re going to go back to, say, 1990 and look at the last 20 years. If we can get the data up through 2015, we’ll do that. Then in another dataset, we’ll have periods of health indicators from 2000 till 2012 or 2013.
Water Deeply: Will you be able to pick up climate change influences?
Schwabe: Our study will look at the impacts of adverse weather events on health. What we could do is look at the climate predictions associated with these regions in, say, 2050. And given the associations we’ve found in our research, what does that suggest about health impacts in 2050 if we assume the climate is only going to get more variable and more extreme? That will only be an estimate because, over 20 years, you figure people will find ways to adapt. But it also suggests if we don’t do anything, here are the best estimates of how our health might be affected.
Water Deeply: Will you be focusing on other extreme weather events, or just drought?
Schwabe: Right now we are interested in focusing on just drought, but also extreme temperatures. Drought isn’t necessarily fully described by the lack of rain. What we’re seeing these days is that periods of dryness are intersecting more and more with period of extreme temperatures.
The drought obviously leads to a lot of dry woodlands, and they’re more susceptible to fires, and the fires often lead to not only denuded landscapes – which lead to mudslides and create erosion and more floods – but also to air pollution. That’s a factor we’ve got to be cognizant of: there are these other effects associated with drought that might be experienced.
Water Deeply: You also plan to look at emotional distress related to drought. That isn’t easily quantified.
Schwabe: I think that’s what is going to be really unique about what we will tease out of this. Typically, economists have looked in the past at how the loss of social and economic resources impact health.
There are expectations about whether I’m going to have a job this summer or not, and what that means for my ability to put food on the table, or give my son or daughter resources to go to school. Those expectations can increase the stress levels within my system. Increases in stress can impact my bodily systems, maybe lower my immune system and add wear and tear both mentally and physically, which can lead to disease and death. We will look for cases where we don’t necessarily observe a change in the social or economic resources that have been available to people, but we still see health impacts.
Water Deeply: What do you hope your research will lead to?
Schwabe: My first goal is to provide a little more light in terms of what are the relationships between adverse weather events and health. Secondly, if we do find the relationship, look at how it is influenced by water policy. Then third, bring that evidence to the public – the water agencies, the resource agencies and the general public – through seminars and journal articles and workshops.
Water Deeply: You have stated that you hope this research leads to a ‘new era of health policy.’ What do you mean by that?
Schwabe: Health is influenced by a whole range of other types of policies that end up being correlated with health or causing health impacts.
So when the State Water Resources Control Board or Department of Water Resources are thinking about water allocations, we want to make them aware, depending on the results of our study, whether their allocations will have impacts on not only agricultural production rates and fish mortality, but also on human health, and where the stressors or spikes might be that they might be able to address. So in that sense, bringing health policy into water policy – providing that evidence.
Also, when I think about agricultural impacts and the loss in revenue of $2.7 billion, that measure alone seems like a short-run cost. If you think about the implications on health and growers’ ability to support their families – nutrition, education and such – the cost can be much longer and greater than I think has been discussed so far in this policy arena. But that’s something that we’ll look into.
My hypothesis is that there are significant and long-range health effects. That’s what we’ll test. It may turn out our results suggest there are not, but that’s why we do the research.
Policymakers are aware that there are these small communities that rely on a single source of water, often groundwater, who end up losing access to that water. What this study will do is expand on that and say: it’s not just reduced access to groundwater, but there is a whole range of other health mechanisms that might be influenced by drought.