Our Latest Perspectives Posts

What is Flu and How Does it Spread?
Written by By the Water Quality & Health Council

As we begin the New Year, flu is spreading in the US. The map below from the Centers for Disease Control and Prevention (CDC) website shows the current geographic distribution of flu. Media coverage of this phenomenon, and unfortunately, our own experience with flu, lead many to ask, “What is flu, and how does it spread?”

Flu View 2

“Flu,” short for “influenza,” is a contagious respiratory illness caused by a group of viruses. Flu viruses can infect the nose, throat, and sometimes the lungs of human hosts, according to the CDC. Flu can cause mild to severe illness (and even death), including cough, sore throat, runny or stuffy nose, muscle or body aches, headache and fatigue. Fever may or may not accompany flu, and young children are more likely than adults to experience vomiting and diarrhea from flu. Some of the symptoms of flu are the same as those of colds. The fluandhealth.org chart, “Is it the Flu or the Common Cold?” can help you distinguish between flu and cold.

How Flu Spreads

History in a Name

“Influenza” is an Italian term for “influence,” based on the historic notion that epidemics were due to the influence of the stars.

Every year from about October to May, seasonal flu viruses circulate among the US population, leading to some hospitalization and death. CDC estimates that the number of US deaths from flu in recent years ranged from a low of 12,000 (in the 2011-2012 flu season) to a high of 56,000 (in the 2012-2013 flu season). The World Health Organization estimates flu infections annually result in between three and five million cases of severe illness worldwide and between 250,000 and 500,000 deaths. The infamous 1918-1919 “Spanish Flu” was a pandemic—a global infection—that infected nearly one-third of the world population and killed at least 40 million people. Researchers note that at approximately 7%, the mortality rate of the Spanish Flu pandemic was about 25 times that of other flu pandemics.1

Flu spreads mostly in colder months when people are most likely to be in close, indoor contact. The most important flu prevention strategy is getting vaccinated every year. Obtaining a “Vaccine by Halloween”2 provides optimum protection, but later vaccination is still very helpful. The vaccine takes about two weeks to become fully protective; flu season typically peaks in February. If you haven’t gotten your flu shot yet, it is not too late!

According to CDC, flu viruses are believed to be transmitted from person to person through small droplets of mucous containing the virus. Coughing, sneezing and even talking can project these droplets into the air, where they may land in the mouths or noses of others. Alternatively, droplets may land on frequently touched surfaces and be transmitted via the hand-to-mouth route. Based on an understanding of these routes of transmission and the potential reduced effectiveness of this year’s vaccine, it will be doubly important to:

  • Stay home and limit contact with others when sick with the flu; consider wearing an anti-viral face mask
  • Cover coughs and sneezes
  • Wash hands frequently and thoroughly
  • Disinfect frequently touched surfaces during flu season3
  • Maintain a healthy lifestyle to optimize your immune system defense

Flu Infection: Like a Key to a Lock

Flu viruses mutate, making it difficult to know which ones will circulate in any given year, which is why we can become sick with flu multiple times throughout our lives. This year’s predominant flu virus strain appears to be an H3N2 variety, the same strain that caused record flu activity in Australia during the last Southern Hemisphere winter. On December 27, 2017, CDC issued a health advisory recommending more and earlier use of antiviral medicines for treatment because (a) H3N2 virus-predominant flu seasons have been associated with more hospitalizations and deaths in older and younger age groups, and (b) flu vaccine effectiveness is generally lower against H3N2 viruses than other types of flu viruses.

According to CDC, when the virus enters your nose, throat, or lungs, a protein on the virus’ surface, known as “hemagglutinin” (representing the “H” in H3N2) binds “like a key to a lock” to receptors on the surface of respiratory tract cells. Once that “key” is inserted, a flu infection has begun. Viruses require living hosts, e.g., you, to survive and multiply. Flu symptoms may appear in one to four days, but you may be contagious starting one day before symptoms appear and five to seven days later, according to an article in the British Medical Journal. As the virus multiplies, your immune system battles the foreign “invaders.” The battle duration, and therefore the period of infection, normally lasts three to seven days, resulting, most often, in victory–and a return to health–for the human host.

Armed with information on what flu is and how flu spreads, we hope you will take steps to avoid becoming a human host for flu!

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1 Loo, Y-M and Gale, M. (18 January 2007). “Fatal immunity and the 1918 virus,” Nature, vol. 445. Online, available: https://vdocuments.site/documents/influenza-fatal-immunity-and-the-1918-virus.html

2 See, for example, this WJHG.com video.

3 Clean surfaces first with detergent and water and then sanitize using 2½ tablespoons of high strength household bleach (8.25%) per gallon of water or ¼ cup regular strength (5.25-6%) bleach. Alternatively, wipe down surfaces with disposable pre-moistened wipes containing chlorine bleach.


Hand-washing for the Holidays is for the Whole Family
Written by By the Water Quality & Health Council

healthy-holidaysAs we gather to celebrate the holidays, the “gifts” we least hope to share are the unseen pathogens that cause colds, flu and other illnesses. Holiday gatherings are prime venues for gift-exchange and, unfortunately, pathogen-exchange.

It’s not rocket science, and most adults know it, but frequent hand-washing can help reduce the “stealth” pathogen-swapping that goes on when folks congregate. The Centers for Disease Control and Prevention (CDC) notes that proper hand-washing is one of the most important steps we can take to avoid getting sick and spreading illnesses to others.

Do your children understand how important hand-washing is to staying healthy? You might start with this kid-friendly, 30 second video from CDC. Additionally, the American Cleaning Institute offers a fun “Clean Your Paws for Santa Claus Coloring Page”. The image caption clarifies that hand-washing “with soap and warm water for 20 seconds” precedes the reward of reaching for a cookie.  Why not print out a few copies, grab a box of crayons, and share them with the children at your holiday gathering?  

Screen Shot 2017-12-19 at 9.37.17 PM
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After All These Years, Was My Mom Right about Removing Your Shoes When Entering a Home?
Written by By Bruce K. Bernard, Ph.D.

One way to encourage shoe removal is to provide an obvious place in the foyer where guests can sit and remove shoes easily.

One way to encourage shoe removal is to
provide an obvious place in the foyer where
guests can sit and remove shoes easily.

My mother always made us take our shoes off just inside the doors of our home. Did that make scientific sense back then or now? Although most of us would not track wet, sandy or muddy shoes into living quarters, many of us routinely make an entrance wearing shoes that are dry and free of visible debris. Mindful of the potential risks from exposure to the invisible microbes adhering to the bottom of their shoes, however, some people leave their footwear at the door. Of course, in some cultures, outdoor shoes are never worn indoors and alternative footwear such as slippers or slipper socks are provided at the entrance to the home.

An April, 2017 Wall Street Journal article concludes that taking your shoes off indoors is both “good manners” and “good hygiene,” but not critical in most cases. With 178+ reader comments posted to the article, it’s pretty clear there are many thoughts on the subject!

Shoe Soles: A Menagerie of Microbes

Studies show the soles of shoes transport a variety of microbes. University of Houston’s Dr. Kevin W. Garey, is quoted in the Wall Street Journal article as saying, “Shoes are a menagerie of microorganisms, sometimes carrying dangerous bacteria.” He implies, however, that unless residents suffer from an underlying condition that makes them susceptible to infection, or they are elderly or very young, they run little risk of getting sick from the microbes clinging to their shoes.

Dr. Garey and his colleagues conducted a study of the prevalence of the superbug bacterium, Clostridium difficile, or “C. diff” on the soles of shoes from the Houston area. The researchers found C. diff on over 25% of the roughly 2,500 shoes sampled. Austrian researchers found at least 40% of shoes sampled carried Listeria monocytogenes (usually transmitted through contaminated foods) and a German study found E. coli (normally found in the intestines of people and animals) on over 25% of boots worn on farms. Wiping your shoes or boots on a door mat may remove some of the debris that harbors microbial pathogens, but the action also likely leaves pathogens there for pickup by the next pair of shoes (or socks or bare feet) to traverse the mat.

Advice for Shoe Wearers

The researchers interviewed for the Wall Street Journal article agree that the risk from leaving your shoes on upon entering living quarters is normally “muted” and “not something to freak out about,” but a pretty good idea. That makes sense, but it also makes sense to scale your actions to the potential risk of exposure of residents in the home to pathogens. For example, if you are entering the home of someone in precarious health or a toddler who is in constant contact with the floor and carpets, stepping out of your shoes is prudent. Otherwise, leaving your shoes at the door is polite and hygienic, but not a “must,” unless required by your host. Overall, use your best judgment.

Bruce K. Bernard, Ph.D., is President of SRA Consulting, Inc., and Associate Editor of the International Journal of Toxicology.  He lives in Cambridge, MD surrounded by nature (e.g., lots of deer [which eat his wife’s tenderly grown flowers and leave droppings everywhere]), and two corgis who, having a doggy door come and go as they please, leaving droppings wherever they want. Thus, he removes his shoes when entering ‘his wife’s home’ (and laughs each time at the memory of his mother yelling to the kids to ‘take your shoes off’)!

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“Germ” Terms: Villains and Heroes
Written by By the Water Quality & Health Council

Germ Terms“Germs,” “pathogens,” “microbes,” “probiotics,” the “human microbiome”… these are just a few of the terms in common use that pertain to the world of microscopic life forms that we alternately avoid and embrace. For example, to steer clear of becoming sick with the seasonal flu virus, many of us get an annual flu shot. Employees are asked to stay home from work to help prevent spreading colds (rhinoviruses) and norovirus (the “stomach bug”), and hospitals disinfect against superbug bacteria, such as MRSA and C. difficile. On the other hand, the medical profession notes the “probiotic” characteristics of the “good bacteria” content of yogurt and fermented foods, such as kimchi, sauerkraut1 and miso. The live cultures in these foods, they say, can help shore up our immune systems to fight off illness. So, are microbes good or bad? The answer is both! The world of microbes to which we are exposed daily contains both villains and heroes.

Pathogens are the Villains

Any microbe that causes disease is a pathogen. (These microscopic forms of life belong to groups such as bacteria, fungi, protozoa and viruses). Consider pathogens such as norovirus, rhinoviruses, MRSA and C. diff, to be undesirable “microbe invaders”; the “bad bugs” that can make us sick. Pathogens are the microbes for which sanitizers and disinfectants are made.

What is a Germ?

“Germ” is an informal term for a microbe that can cause disease. In that sense, germs are better described as pathogens. The term originated from the word “germinate” in the 17th century. Pathogens are just a sub-set of all the microscopic life in and on our bodies and present in our environments.

The Germ Theory of Disease was a major scientific breakthrough that states that specific microscopic organisms are the cause of specific diseases. According to the Harvard University Library Open Collections Program, “germ theory revolutionized the theory and practice of medicine and the understanding of disease.”

Before Germ Theory became accepted in the period from 1850 to 1920, scientists thought that disease was caused by an imbalance of the four “humors,” or bodily fluids: black bile, yellow or red bile, blood and phlegm. The Humoral Theory of Disease is associated with Hippocrates (460-370 BCE) and remained dominant among physicians and the public through much of the 19th century.

Pathogens are not to be confused with the ten thousand species of microbes that inhabit our bodies naturally and help us digest food, absorb nutrients and produce vitamins and compounds that naturally suppress inflammation in our intestines. These are the constituents of the “human microbiome.” Each of our bodies is its own microbial ecosystem, comprising bacteria, virus and fungi populations numbering in the trillions. In fact, our human microbiome—the collective genome (all the genes) of all resident microbes—is larger than our human DNA.

A Balanced Approach to Cleanliness

The Hygiene Hypothesis says that the effect on children of excessive cleanliness is that their immune systems may be underdeveloped, explaining the modern rise in childhood allergies and decline in immune system performance. At the “Excellence in Paediatrics Conference” in Madrid, one report suggested that the Hygiene Hypothesis be replaced by the Old Friends Hypothesis. “Old friends” are the microbes that were present when humans evolved, not the more recent microbes that cause infectious illness, which we commonly think of as “germs.”

According to a New York Times article on the report, we need exposure to some types of microbes to regulate our immune system but not to the germs that cause infectious diseases. “Worrying about ‘being too clean’ could result in people needlessly exposing themselves and their children to pathogens that can make them ill, which would clearly be dangerous,” notes the article. The experts would encourage parents to distinguish between “letting children have contact with their environment and getting dirty while also protecting them, as far as possible, against potentially harmful microbes.” This means letting children play and interact with the outdoor environment, but setting rules about hygiene such as washing hands after using the bathroom, before eating and after touching pets or farm animals.

We agree with this balanced approach. For one thing, children are curious creatures who should be given a chance to interact with the outdoor environment. The Old Friends Hypothesis tells us this is a healthy attitude toward cleanliness that will help expose them to microbial heroes. And by teaching children the time-honored basics of hygiene, they will be protected sufficiently from microbial villains.

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1 the type containing live cultures


A Thanksgiving Food Safety Quiz
Written by By Linda F. Golodner

Wondering how long your leftover holiday food will last once refrigerated or frozen? Consult this handy Foodsafety.gov chart.

Wondering how long your leftover holiday food will last once refrigerated or frozen? Consult this handy Foodsafety.gov chart.

Preparing a Thanksgiving feast is really an exercise in project management. Whether you are “sub-contracting” the sides or coordinating everything from “soup to nuts” yourself, an awareness of food safety is essential to reach the goal of a delicious, safely prepared meal. Take the quiz below to test your knowledge of food safety for the big day ahead.

True or False:

1. The top shelf of the refrigerator is the worst place to store a raw turkey until it is time to be cooked.

True. Store Tom Turkey “as low as he can go” in the fridge; that is, on the lowest shelf possible. The goal is to prevent raw turkey juices from dripping down and contaminating foods stored on lower shelves. Keep Tom well-wrapped in plastic and on a tray large enough to catch all raw juices.

2. It is not necessary to wash fruits and vegetables that will be peeled.

False. During food preparation it is best to wash all fruits and vegetables using cold, running water. Remember that as you peel and slice, bacteria from outer skins can be transferred to the insides of produce via your knife or peeler. This is especially important when preparing vegetables that will not be cooked, such as raw fruit and vegetable platters.

3. It is essential to rinse a raw turkey with cold, running water before preparing it for the oven.

False. According to the U.S. Department of Agriculture (USDA), rinsing a raw turkey in the kitchen sink can generate a fine spray of germ-contaminated water that settles on surrounding surfaces up to three feet away, including countertops, other food, kitchen towels and you! Skip this rinsing step to avoid showering yourself and your kitchen with Tom Turkey’s germs! They will be destroyed in the cooking process.

4. Cutting boards used for raw fruits and vegetables should not be reused for raw meats, poultry and fish.

True. In the busy holiday kitchen, it’s best to designate a separate cutting board for raw vegetables and one for raw meats, poultry and fish. That will help reduce the risk of cross-contamination. Between uses, USDA recommends washing your cutting board with hot, soapy water, then sanitizing it with a dilute chlorine bleach solution made by mixing ½ tablespoon of bleach with ½ gallon of clean water.

5. Foods can remain on the dinner table for 3-4 hours before being refrigerated for future consumption.

False. Time flies when you are having fun, but don’t lose track of the time your dinner sits on the Thanksgiving table. Leftovers will be safe for Black Friday and a bit beyond if you refrigerate them no longer than two hours after placing them on the table, according to the USDA. And it is not necessary to cool down hot dishes before refrigerating or freezing them. Maintain the refrigerator temperature at 40 degrees F or below, and the freezer temperature at 0 degrees F or below.

The 4 C’s of Sink Safety

Keep fats, oils and grease (FOG) from going down your kitchen sink drain and damaging plumbing. Who wants to call a plumber on Thanksgiving? DC Water advises:

  • Cool: After cooking, allow grease to cool and solidify in the pan.
  • Contain: Scrape FOG and excess food scraps into a secure, sealable container, like a peanut butter jar. Before washing the pan, wipe down with a paper towel.
  • Can: Throw the full container of FOG and your paper towel into a trashcan.
  • Compost: If possible, compost food and vegetable scraps (don’t compost grease).

6. You can always tell when food has spoiled because it will have an “off” odor.

False. While an off-odor probably indicates food spoilage, sniffing is not a fail-safe test of freshness, according to USDA. Some foods may be contaminated with bacteria and not smell “off.” Follow basic food safety principles: abide by expiration dates; separate and store foods properly, refrigerating when required; cook to recommended temperatures; and don’t take chances: when in doubt, throw it out!

7. Washing your hands frequently helps avoid your becoming an agent of cross-contamination in your own kitchen.

True. As you dash around your holiday kitchen, stay mindful of the fact that your hands can become a vehicle for foodborne germs to transfer from one surface to another. Wash your hands for 20 seconds using warm water and soap between kitchen tasks, but especially after contacting raw foods or using the bathroom. Children often eagerly help prepare and serve food at Thanksgiving; make sure they know how important it is to wash their hands thoroughly before and after helping.

Lastly, remember that disposable gloves can be sanitary and useful, but they too can transfer germs from one surface to another, so they should be changed between tasks.

Have a delicious, safe and fabulous Thanksgiving!

Linda F. Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.

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How to Keep Your Halloween Jack-o-Lantern Looking Fresh and Teach Your Kids a Little Science in the Process
Written by By Linda F. Golodner

jackolanternCarving Jack-o-lanterns is a fun Halloween tradition. Whether you transform your pumpkin into an exquisite work of art or a sweet smiley face with triangle eyes, preserving your Jack-o-lantern from mold and mildew can be tricky. But here’s a Halloween treat of a hint: Jack-o-lanterns can be preserved for a short time with the help of a dilute solution of chlorine bleach.

Dunking Jack

The directions below are based on a recommended procedure found on the Clorox website for extending the “porch life” of your Jack-o-lantern.  

  • After cutting the top of your pumpkin off, use a spoon to remove seeds and stringy fibers from the inside of the pumpkin and the underside of its top. (If you have one, a grapefruit spoon – with a serrated edge – is a great tool to help dislodge fibers.) Consider collecting the pumpkin seeds for roasting and snacking.
  • Rinse the inside and outside of the pumpkin with tap water.
  • Carve your Jack-o-lantern masterpiece.
  • In a 5-gallon bucket or a large sink, prepare a solution of 3 teaspoons of 8.25% bleach1 in 3 gallons of water.
  • Immerse your Jack-o-lantern into the solution and stir it around to ensure 2 full minutes of contact of every part of the Jack-o-lantern with the solution; remember to immerse the Jack-o-lantern top too. The Jack-o-lantern will float, so keep pushing it down with a spatula or your plastic-gloved hand to ensure full immersion.
  • Remove the Jack-o-lantern and its top from the solution and place them on newspaper or paper towels to dry.
  • Pour the bleach solution down the drain. (Once used, the solution will not last for a repeat treatment in a few days – a new solution will have to be made.)

Halloween Science

When the kids ask you why you are dunking their poor Jack-o-lantern in a bucket or sink full of bleach solution, seize the moment to impart a brief science lesson, complete with Halloween themes of decay and vampire-like attack. Here are your “talking points”:

  • Pumpkins, like all vegetation, decay slowly over time. Carving a pumpkin speeds up the decay process because:
    • You have cut into the fruit, exposing the inner “flesh” to oxygen in the air. Oxygen combines with some of the chemical substances in the flesh of the pumpkin, breaking them down chemically. [And, yes, pumpkins are classified as fruit because they have multiple seeds, which you will be confronted with in droves when you carve yours! They make a wonderful snack.]
    • In the process of cutting into the pumpkin, you have likely transferred bacteria from the outer surface of the pumpkin to the inner flesh (although there may be fewer bacteria as a result of your rinsing the pumpkin before carving). Those bacteria that “hitched a ride” on your carving knife assist in the decay process by “feeding,” vampire-like, on chemical substances in the pumpkin such as natural sugars.
    • Dunking your Jack-o-lantern into a solution of chlorine bleach helps destroy “vampire” bacteria and mold, thereby helping to preserve it a bit longer on the front porch. With any luck, and especially if the outside temperature does not run too high, your “treated” Jack-o-lantern will be in fine shape for Halloween. [Most chemical reactions run faster when the temperature rises; cold slows them down, which helps preserve the Jack-o-lantern.] Storing your Jack-o-lantern in the fridge for a few days is certainly an option, if you have the space!

Here’s to a fun-filled Halloween!

Linda F. Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.

Click here to download this article.

1 Sometimes called “regular” bleach and sometimes called “concentrated” bleach


Controlling the Spread of Invasive Aquatic Species with the Ballast Water Management Convention
Written by By Chris Wiant, M.P.H, Ph.D.

Ballast Water Release

Ballast Water Release

Ballast water is the marine or fresh water taken into the ballast tank of a ship to improve the vessel’s stability, buoyancy and maneuverability. Unfortunately, the process of adding and subtracting ballast water, so vital to a ship’s operation, can have unintended consequences for aquatic ecosystems.

Ballast water may include aquatic life forms native to the ecosystem of the water “take in” point, but foreign to the ecosystem of the water “release” point. This watery exchange can promote the spread of invasive aquatic species, a global environmental issue that is the subject of the Ballast Water Management Convention. The Convention requires participating nations to have a ballast water management plan to help avoid disrupting native ecosystems with invasive aquatic species.

Many Years in Development

Zebra mussels are freshwater mussels originally indigenous to lakes and rivers of Russia and Ukraine; they are now thriving in numerous bodies of fresh water worldwide. Their dense growth blocks pipelines and clogs water intakes, among other detrimental effects.

Zebra mussels are freshwater
mussels originally indigenous to
lakes and rivers of Russia and
Ukraine; they are now thriving in numerous bodies of fresh
water worldwide. Their dense
growth blocks pipelines and clogs water intakes, among other
detrimental effects.

The new Convention is an initiative of the International Maritime Organization (IMO), a specialized agency of the United Nations. The Convention was adopted in 2004, but did not “come into force” until September 8, 2017, “twelve months after the date on which not less than 30 ‘states’ [a state is a nation in ‘UN speak’] with combined merchant fleets of not less than 35% of the gross tonnage of the world’s merchant shipping have signed it,” according to the official convention language. Although a ballast water management plan is a requirement for those nations that have ratified the Convention, many ships from both ratifying and non-ratifying nations already implement ballast water management plans.

Rooting out Aquatic Stowaways

There are two ballast water management tools through which the maritime industry can be regulated. The first is through the Ballast Water Exchange Standard, which requires ships to exchange a minimum of 95% ballast water volume at least 50 nautical miles from the nearest shore and in waters of 200 meters depth or more. This helps prevent invasive species spread in coastal and shallow waters that may be most vulnerable to the problem.

The second tool, the Ballast Water Performance Standard, involves meeting limits for aquatic organisms, including Vibrio cholera and E. coli in the ballast water. These water quality limits may be achieved through physical and/or chemical treatment methods. Among physical treatment methods are filtration, heat and UV radiation. The most common chemical methods used are chlorine-based disinfectants, such as chlorine bleach (a solution of sodium hypochlorite and water). Other chemical methods include ozone, peracetic acid and chlorine dioxide.1

Weighing the Risk of Disinfection Byproducts

Some concern has been expressed over the unintentional production of disinfection by-products (DBPs) from ballast water treatment and the potential health and environmental effects on aquatic life of DBPs in released ballast water. DBPs are unwanted products of the chemical reaction between disinfectants and organic matter in water. To avoid the potential human health effects from exposure to DBPs in municipal chlorinated drinking water, for example, the US Environmental Protection Agency regulates the most common DBPs to levels based on the best available science, incorporating a margin of safety. In weighing the risks of exposure to DBPs in drinking water, versus not disinfecting water appropriately, the World Health Organization notes:

“In attempting to control DBP concentrations, it is of paramount importance that the efficiency of disinfection is not compromised and that a suitable residual level of disinfectant is maintained throughout the distribution system.”2

Similarly, if we wish to control the spread of aquatic invasive species, we must evaluate a risk versus risk scenario in which we ask: Is it better to disinfect ballast water (to help prevent the spread of invasive species) or not disinfect ballast water (for fear of DBPs entering the aquatic environment)? This is the type of evaluation we perform when we decide, for example, whether it is better to get the annual flu shot (to help avoid the flu) versus not getting the flu shot (for fear of potentially rare side effects). Whereas most DBP research to date has been focused on drinking water, further work is needed to identify and evaluate the toxicity to marine life of DBPs produced and released in ballast water, especially marine ballast water.

According to the IMO, over 90% of the world’s trade is carried by sea because it is “the most cost-effective way to move en masse goods and raw materials around the world.” We think the entry into force of the Ballast Water Management Convention is a giant step in the right direction toward curtailing the unintended but potentially harmful spread of aquatic invasive species.


Chris Wiant, M.P.H, Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council and a member of the National Drinking Water Advisory Council.

Click here to download this article.

1Werschkun, B. et al. (2014). Emerging risks from ballast water treatment: The run-up to the International Ballast Water Management Convention. Chemosphere, v. 112, Oct. 2014, pp. 258-266. On line, available: http://www.sciencedirect.com/science/article/pii/S0045653514005268.

2 WHO (2011). Guidelines for Drinking-water Quality, 4th Edition, WHO Press: Geneva, Switzerland. On line, available: http://apps.who.int/iris/bitstream/10665/44584/1/9789241548151_eng.pdf



Getting Hepatitis A Off the Streets of San Diego
Written by By Ralph Morris, M.D., M.P.H.

Hepatitis AA Hepatitis A outbreak centered on homeless and illicit drug-using populations in the County of San Diego, California, has prompted a public health emergency. Headline-grabbing responses by local officials describe washing the streets and sidewalks with chlorine bleach solution, aggressively vaccinating the vulnerable populations, and distributing personal hygiene kits. What caused this local outbreak and can these measures help mitigate it?

The Facts about Hepatitis A

Hepatitis A is a highly contagious viral disease that affects the human liver, according to the US Centers for Disease Control and Prevention (CDC). It is usually spread through the fecal-to-oral route, either by person-to-person contact or by consuming contaminated food or water.

Before the era of drinking water chlorination, over a century ago, Hepatitis A, along with typhoid fever and cholera, was one of the great waterborne scourges of American life. Today chlorine-based disinfectants are routinely used during water treatment to destroy the Hepatitis A virus along with a host of other potentially deadly microbes.

Hepatitis A infections can range in severity from a mild illness of a few weeks to a severe illness lasting several months, according to CDC; although rare, it can cause acute liver failure. Overall, US Hepatitis A infection rates are low, probably as a result of the vaccine’s wide availability. Yet, over 400 people in San Diego have been infected since the start of the local outbreak; 292 people have been hospitalized and 16 have died of the disease, according to the County of San Diego Health & Human Services Agency. How did this happen?

Missing: A Sanitary Environment

High on the list of factors contributing to the outbreak is an apparent shortage of public restrooms in areas where homeless people and illicit drug users congregate. This apparently has led to some open defecation. An August 31 directive from the County instructed the city to wash streets and sidewalks with diluted household bleach solution (providing explicit directions) and expand public restroom and hand-washing access. San Diego Councilwoman Lorie Zapf, in a KPBS interview, said she had visited the San Diego River region in July and saw “an insane amount of trash” that included human feces, meth cookers, syringes and stolen property.

The county directive will help reduce human contact with fecal matter and infected surfaces. These measures will impose a needed barrier along the fecal-to-oral route of the virus’ transmission, helping to prevent not only Hepatitis A but potentially several other diseases known to spread via the same path.

The best way to prevent Hepatitis A is by getting vaccinated and maintaining good personal hygiene and sanitation. The vaccine, introduced in 1995, and now routinely administered to US children, travelers to certain countries, and persons at risk for the disease, lasts a lifetime, protecting against reinfection. Since the beginning of the outbreak in March, there have been over 250 mass vaccination events, and nurses deployed to areas frequented by the homeless, according to an NPR report.

Homelessness and illicit drug use remain significant societal issues, which must be addressed. Meanwhile, we have the tools at our disposal to combat this public health emergency and get Hepatitis A off the streets of San Diego. Key to our long term public health success will be using the lessons learned in San Diego to help prevent future emergencies of the same kind.


Ralph Morris, M.D., M.P.H., is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.

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Cleaning up After Hurricane Harvey: Chlorine Bleach Is Your Friend
Written by By the Water Quality & Health Council

Houston residents walk across a flooded street on August 27, 2017. Hurricane Harvey dumped trillions of gallons of water in several Gulf states, leading to devastating flooding.

Houston residents walk across a flooded street on August 27, 2017. Hurricane Harvey dumped trillions of gallons of water in several Gulf states, leading to devastating flooding.

After the shock and heartbreak of experiencing a flood comes the clean up to prevent further damage and spread of disease. Flood cleanup starts with removing flood water (usually contaminated with sewage) and drying the affected areas. Evaluate all items touched by flood waters, deciding which to keep and which to toss. Whenever possible, use a disinfecting solution of chlorine bleach to disinfect items touched by flood waters.

  • When using a disinfecting solution to clean up after a flood, remember to:
    • Wear gloves and protective clothing. Do not touch your face or eyes.
    • Change the disinfecting solution often and whenever it is cloudy.
    • Be thorough. Wash and dry everything well.
    • When finished, wash your hands thoroughly with soap and water for at least 20 seconds, even if you have worn gloves.
    • Wash contaminated clothing in the hottest possible water with detergent and chlorine bleach if fabric instructions permit.
  • If an item got wet, assume it is contaminated.
  • Disinfecting works best when all loose dirt and debris are removed first. That’s why the CDC recommends first washing surfaces with soap and warm, clean water. Next, use a household bleach solution to disinfect.
  • Prepare a bleach solution (3/4 cup regular strength chlorine bleach or 1/2 cup concentrated bleach to one gallon of water) to disinfect walls, floors and other surfaces touched by floodwaters. Keep the area wet for at least two minutes.
  • When addressing exterior surfaces, such as outdoor furniture, patios, decks and play equipment, keep surfaces wet with disinfecting solution for 10 minutes after removing loose dirt and debris with soap and warm, clear water. This may mean wetting the surface with disinfecting solution more than once.
  • Carpets and rugs that have been soaked for more than 24 hours should be discarded. If carpets and rugs were soaked for less than 24 hours, evaluate as follows: Carpets that contacted sewage-contaminated floodwater should be discarded. Carpets that contacted only clean basement seepage or lawn runoff may be dried and cleaned. Washable throw rugs usually can be cleaned adequately in a washing machine. For more information on cleaning flood-damaged carpets and rugs, see this North Dakota State University website.
  • Chlorine bleach solutions degrade quickly, so be sure to make a fresh solution daily as needed. Unused solution may be discharged into the toilet or sink.

Finally, if you have a private well on your property that is below flood level, it is recommended that under non-flood conditions you extend the top of the well above the expected flood level and install proper seals on all openings into the well to prevent entry of flood waters. If a well is flooded, refer to the US Environmental Protection Agency’s What to Do After the Flood for directions on decontaminating your well.

This article is excerpted from a more comprehensive article posted on August 11, titled “Preparing for the Next Flood and its Aftermath.”

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Kitchen Sponges: Cleaning Tool or Germ Dispenser?
Written by By the Water Quality & Health Council

The notorious kitchen sponge—that germ-ridden object found in many households—is at the center of a new controversy about controlling the spread of infections in the home. Several years ago we reported a University of Florida research team found microwaving spongevery wet sponges for two minutes at high power killed or inactivated over 99 percent of all the living pathogens in sponges and cleaning pads that had been soaked in a “witch’s brew of germs.” Easy and convenient, right? Think again: A team of German researchers using genetic techniques to characterize sponge microbes says that neither boiling nor microwaving sponges may be particularly effective in the long run. Careful testing of alternative sponge treatments is needed, but in the meantime, the researchers recommend the best course may be ditching your kitchen sponge once per week for a new one.

Sponge Microbe Dynamics

First, the German team found the density of bacteria in some portions of 14 German kitchen sponge samples to be equivalent to that found in feces! Significantly, their data show “…regularly sanitized sponges (as indicated by their users) did not contain less bacteria than uncleaned ones.” But in an interesting, Darwinian twist, the researchers suggest the most resistant bacteria in sponges preferentially survive boiling or microwaving, only to repopulate the sponge rapidly after these treatments. Some of these are more pathogenic too, for example, “RG2-related bacteria” identified in the test sponges may have the potential to cause diseases in humans. The scientists state, “…a prolonged application of sanitation measures of kitchen sponges is not advisable.” In other words, the more you “challenge” sponge microbes with disinfection, the more you may encourage the survival of the fittest and most likely to make you sick.

Because kitchen sponges are moist, have high surface area, and are frequently wiped over food preparation and dining surfaces, they are a major agent of cross-contamination. Ironically, the more kitchen surfaces are wiped by the conscientious house cleaner with a contaminated sponge, the more contaminated the surfaces may become. For example, one of the resistant bacteria shown to survive treatment, Moraxella osloensis, is common in sponges and is found consistently on sink, faucet, refrigerator door and stove surfaces. You may have smelled Moraxella; it imparts a disagreeable odor to sponges and laundry.

Scientific Inquiry is Open-ended

The new study demonstrates the ongoing nature of scientific investigation: What we once thought true may not stand the test of the next investigation. The scientific method requires continual testing and reformulation of hypotheses based on meticulously collected data. The scientific method does not guarantee that any given conclusions are correct. The German researchers correctly note that additional studies in this area are needed. We agree and wonder if soaking kitchen sponges regularly in appropriate chlorine bleach and water solutions would be effective. For now, the advice to replace sponges weekly is prudent, but stay tuned!

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