CDC on the Connection between Drought and Public Health
Healthy Living Healthy Planet Radio's episode titled: "The Environmental, Health and Economic Impacts of Drought" aired this past Saturday, November 14th on 1190 AM KXFR and although an expert from the Center for Disease Control was not able to join us physically, they have compiled their extensive knowledge on the connection between public health, clean drinking and recreating water and drought for our listeners in the written interview below.
A special thank you to the Center for Disease Control for you resources, information and partnership. We look forward to featuring you on an episode of HLHP Radio in the future.
Enjoy the CDC’s answers to our interview questions below…
1) When many Americans think of drought, they may think of shorter showers or turning their sprinklers off in the summer, but drought is intrinsically linked to our health and wellness, can you tell our listeners how drought impacts them on a personal level?
Drought can affect health and wellness in a number of ways. This was clearly demonstrated during the 2011–2016 California drought, which was characterized by low precipitation combined with record high temperatures that led to significant socioeconomic and health impacts. In late 2015, California was in the fourth year of its most severe drought since becoming a state in 1850, with 63 emergency proclamations declared in cities, counties, tribal governments, and special districts. Households in two drought-stricken counties (Tulare and Mariposa) reported a range of drought-related health impacts, including increased dust leading to allergies, asthma, and other respiratory issues and acute stress and diminished peace of mind.
Drier conditions can increase the airborne spread of a fungus found in soils, potentially leading to the disease coccidioidomycosis, or Valley fever. Coccidioidomycosis can cause persistent flu-like symptoms, with over 40% of cases hospitalized and 75% of patients unable to perform their normal daily activities for weeks, months, or longer. Higher numbers of cases in Arizona and California are associated with periods of drier conditions as measured by lower soil moisture in the previous winter and spring, although differences in the timing and amount of rainfall can have complex effects on this fungus. The range of this fungus is expected to expand in the coming decades as areas generally too cool and moist for this fungus to thrive become hotter and drier. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GH000209
Overall, the impacts of drought on hospital admissions and deaths depend on drought severity and the history of droughts in a region. Complex relationships between drought and its associated economic consequences, particularly the interactions among factors that affect vulnerability, protective factors, and coping mechanisms, can increase mood disorders, domestic violence, and suicide.
2) How do climate change and drought connect?
Climate change has already contributed to significant changes in water quantity and quality across the country. Variable precipitation, rising temperatures, and depletion of groundwater are intensifying droughts in some areas. These changes, which are expected to persist, present an ongoing risk to human and natural systems.
For more information, see the Water chapter of the fourth National Climate Assessment: https://nca2018.globalchange.gov/chapter/3/
3) Last month we spoke about Climate Change, allergies and asthma, but drought is also a big trigger for lung-related illness, why is this?
The dusty, dry conditions and wildfires that often accompany drought can harm health. Fire and dry soil and vegetation increase the number of particulates that are suspended in the air, such as pollen, smoke, and fluorocarbons. These substances can irritate the bronchial passages and lungs, making chronic respiratory illnesses like asthma worse. This can also increase the risk for acute respiratory infections like bronchitis and bacterial pneumonia.
Other drought-related factors affect air quality, including the presence of airborne toxins originating from freshwater blooms of cyanobacteria. These toxins can become airborne and have been associated with lung irritation, which can lead to adverse health effects in certain populations.
For more information, see: https://www.cdc.gov/nceh/drought/implications.htm
4) How does drought impact our access to safe drinking water?
Reduced stream and river flows can increase the concentration of pollutants in water and cause stagnation. Higher water temperatures in lakes and reservoirs lead to reduced oxygen levels. These levels can affect water quality. Viruses, protozoa, and bacteria may pollute both groundwater and surface water when rainfall decreases. People who get their drinking water from private wells may be at higher risk for drought-related infectious disease. Additionally, people relying on private wells may have reduced water yield or lose access to water if static water levels decrease. Other groups also at increased risk include those who have underlying chronic conditions.
Many parts of the United States depend on groundwater as a primary source of water. Over time, reduced precipitation and increased evaporation of surface water mean that groundwater supplies are not replenished at a typical rate.
5) How does drought impact our access to safe seafood?
Please contact USDA with this question.
6) Drought also impacts the water we swim and cool off in, how is our health at risk when we recreate in water in times of drought?
Untreated recreational bodies of water such as lakes rivers and streams can always be a potential source of exposure to contaminants. People who engage in water-related recreational activities during drought may be at increased risk for waterborne disease caused by bacteria, protozoa, and other contaminants such as chemicals and heavy metals. Exposure can occur through accidentally or intentionally swallowing water, direct contact of contaminants with mucous membranes, or breathing in contaminants.
Untreated surface water can be a health threat in drought conditions. In untreated surface waters, some pathogens, such as a type of amoeba (Naegleria fowleri), are more common during drought because low water levels result in less dilution and may create warmer water temperatures that encourage their growth.
As the levels of surface waters used for boating, swimming, and fishing drop, the likelihood of injury increases. Low water levels in lakes can put people at risk for life-threatening injuries resulting from diving into shallow waters or striking objects that may not be immediately visible while boating. Low surface water levels can also expose potentially dangerous debris from the bottom of lakes, rivers, and ponds.
7) Vector-borne illnesses are also connected to drought, can you break down the connection for our listeners?
In periods of limited rainfall, both human and animal behavior can change in ways that increase the likelihood of other vector-borne diseases. For instance, during dry periods, wild animals are more likely to seek water in areas where humans live. Fewer water resources can also lead to an increased chance of mosquitos interacting with animal hosts. These behaviors increase the likelihood of human contact with wildlife, the insects they host, and the diseases they carry.
Drought reduces the size of water bodies and causes them to become stagnant. This provides additional breeding grounds for certain types of mosquitoes, especially those that can transmit West Nile virus. Outbreaks of West Nile virus, which is transmitted to humans via mosquitoes, have occurred under such conditions. Inadequate water supply can cause people to collect rainwater. This can lead to collections of stagnant water that can become manmade mosquito breeding areas.
8) How can the everyday individual make changes to protect their mental and physical health from the impacts of drought?
People can protect themselves from the health impacts of drought using three strategies:
Be Prepared. Monitor dry weather conditions, learn about water resources, learn about potential behavioral health needs, and plan ahead.
Be Aware. Monitor air quality, water usage, local water levels, and food supply and nutrition.
Be Safe. Follow sanitary guidelines, prevent fires hazards, and protect water supply.
For more information, see: https://www.cdc.gov/nceh/drought/toolkit/default.htm
9) What health complications arise as a result of these pollutants in our drinking water?
Drought and reduced precipitation can have the effect of concentrating contaminants in water sources used for drinking. Treatment systems for both public water systems and private wells may not be designed to effectively treat changing source water impacted from drought, which can cause illness.
Based on information for the CDC National Outbreak Reporting system, the two most common illnesses associated with waterborne disease outbreaks from public water systems were acute gastrointestinal illness from multiple pathogens (like hepatitis) and acute respiratory illness caused by Legionella. For individual water systems, non-Legionella bacteria and hepatitis were the most common contaminants associated with waterborne disease outbreaks. Also, other harmful substances that can get into private well water include nitrates, arsenic, lead and others.
Commonly encountered contaminants in waterborne disease outbreaks (Gunther et al, 2010) include
The most common bacterial cause of diarrheal illness in the United States.
Campylobacter jejuni is the species that causes most human illness world-wide.
Symptoms include diarrhea (often bloody), fever, stomach cramps, nausea, and vomiting.
Bacteria can get into drinking water through sewage overflows, sewage systems that are not working properly, polluted storm water runoff, and agricultural runoff.
More information: https://www.cdc.gov/campylobacter/symptoms.html
Symptoms include fatigue, nausea, stomach pain, and jaundice.
Hepatitis A virus can get into drinking water through sewage overflows, sewage systems that are not working properly, and polluted storm water runoff.
More information: https://www.cdc.gov/hepatitis/hav/index.htm
Bacteria found naturally in freshwater environments, like lakes and streams.
It can become a health concern when it grows and spreads in human-made building water systems.
People can get Legionnaires’ disease or Pontiac fever when they breathe in small droplets of water in the air that contain the Legionella
More information: https://www.cdc.gov/legionella/about/index.html
10) What are some examples of these waterborne illnesses? What are their short-term and long-term effects?
Illnesses associated with fresh or marine recreational water can be caused by pathogens or chemicals, including toxins. The top four, according the CDC’s National Outbreak Reporting System (NORS), are:
Norovirus – short-term symptoms: diarrhea, vomiting, nausea, stomach pain; more information available at: https://www.cdc.gov/norovirus/about/symptoms.html
Shiga toxin–producing Escherichia coli (STEC) - short-term symptoms: severe stomach cramps, diarrhea (often bloody), and vomiting; more information available at: https://www.cdc.gov/ecoli/general/index.html.
Cryptosporidium - short-term symptoms: watery diarrhea, stomach cramps or pain, dehydration, Nausea, vomiting, fever, and weight loss; more information available at: https://www.cdc.gov/parasites/crypto/illness.html.
Shigella - short-term symptoms: diarrhea (sometimes bloody), fever, stomach pain, feeling the need to pass stool [poop] even when the bowels are empty; more information available at: https://www.cdc.gov/shigella/symptoms.html. Vanden Esschert KL, Mattioli MC, Hilborn ED, et al. Outbreaks Associated with Untreated Recreational Water — California, Maine, and Minnesota, 2018–2019. MMWR Morb Mortal Wkly Rep 2020;69:781–783. DOI: http://dx.doi.org/10.15585/mmwr.mm6925a3
11) Water isn't limited to hydration and recreation, water impacts every part of our lives, particularly hygiene. How does drought impact our access to clean water for washing our clothes, bodies, and food?
During drought and when water access is limited, the risk for infectious disease increases when hygiene is not maintained. For instance, many types of infectious disease, including those that cause acute respiratory and gastrointestinal illness, are more easily spread from person to person when hand washing is compromised by a perceived or real lack of available water.
Centers for Disease Control and Prevention. Water-related hygiene. Atlanta: U.S. Department of Health and Human Services. Available at http://www.cdc.gov/healthywater/hygiene/index.html [accessed 2020 November 11].