Thursday, March 31, 2016

Air Pollution from Cars Tied to Dementia

An new study published this week in the National Institute of Health’s journal “Environmental Health Perspectives” has identified a very strong association between air pollution from automobiles and vascular and Alzheimer’s disease dementia. Dementia takes a heavy toll on the patient, the patient’s close relatives, and society as a whole, and is a growing concern as populations live longer.

The effects of air pollutants on heart, lung and circulation function are at this point well established. However, at this point there is growing evidence indicating that air pollution also causes cognitive effects and central nervous system disease. The number of studies suggesting an association between traffic pollution and cognitive function in adults is increasing. A study in Germany where the exposure to traffic-related particulates was estimated by the distance to the closest busy road, found an association between traffic-related particle exposure and mild cognitive impairment. In the Nurses’ Health Study Cognitive Cohort, which included 19,409 elderly women in the United States found that long-term exposure to particulates was found to be associated with faster cognitive decline, and a 10-μg/m3 increment in long-term particulate matter (both PM2.5 and PM2.5–10) exposure was cognitively equivalent to aging by approximately 2 years.

Particulate matter has immediate health impacts: itchy, watery eyes, increased respiratory symptoms such as irritation of the airways, coughing or difficulty breathing and aggravated asthma. However, in long term exposure to particulate pollution the particles can travel deep into the lungs, enter the bloodstream, and penetrate into cells. Particulate matter is made up of particles that are emitted directly, such as soot and dust, as well as secondary particles that are formed in the atmosphere from reactions of precursor pollutants such as oxides of nitrogen (NOx), sulfur oxides (SOx), volatile organic compounds (VOCs), and ammonia (NH3).

Particle are either directly emitted or formed in the atmosphere. Directly-emitted particles come from a variety of sources such as cars, trucks, buses, industrial facilities, power plants, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood. Other particles are formed indirectly when gases produced by fossil fuel combustion react with sunlight and water vapor. Many combustion sources, such as motor vehicles, power plants, and refineries both emit particles directly and emit precursor pollutants that form secondary particulates.

In the current study the researchers utilized the data in the longitudinal Betula study. Betula study was created and designed to explore various aspects of health and cognitive aging, including early signs of and potential risk factors for cognitive decline and dementia in adulthood and late life. Betula project studies lifestyle, environment, health and how memory functions change during adult life and old age, to identify risk factors for dementia and to identify early preclinical signs of dementia. The participants of the project have (so far) been tested, interviewed and examined medically on six occasions (1988-1990, 1993-1995, 1998-2000, 2003-2005, 2008-2010 and 2013-2014) in the past quarter century. The Betula study area is a small city in Sweden called Umea.

The study used the annual mean NOx concentration at the participant’s home address to represent the long term exposure to air pollution. The researcher found that the proportion of participants diagnosed with dementia increased with increasing NOx concentration at the participant’s homes. The model was adjusted for age and ApoE4, education, physical activity , smoking, sex, alcohol use BMI and still the data showed the correlation between air pollution and developing dementia. The presence of intermedate factors of hypertension, diabetes and stroke which are risk factors for dementia was also adjusted and still the proportion of participants diagnosed with dementia increased with increasing Nox concentration at the participants home.

Though Umea is a city with very low regional background levels of air pollution, there are still significant air pollution gradients within the city. Air pollution is hyper local and are tracked within the city and modeled. The major source of NOx pollution in the city is vehicle exhaust from local traffic. The results of the present study are a strong indication that air pollution may cause dementia and further research needs to be done. Meanwhile think about your own exposure to vehicle pollution. How's your air quality today?

Citation: Oudin A, Forsberg B, Nordin Adolfsson A, Lind N, Modig L, Nordin M,
Nordin S, Adolfsson R, Nilsson LG. 2016. Traffic-related air pollution and dementia incidence in northern Sweden: a longitudinal study. Environ Health Perspect 124:306–312; 

Monday, March 28, 2016

Do You Have Lead in Your Drinking Water?

You might have lead in your drinking water, but lead does not exist in in most groundwater, rivers and lakes- the source water for most municipal and private water supplies. In addition, water treatment plants as required by the Safe Drinking Water Act test for lead before the water leaves the plant. It is exceedingly rare to have lead in groundwater or rivers as a result of pesticides that were used decades ago or industrial activity that contaminated soil and groundwater. However, it has been estimated that 20% of urban households and an unknown number of rural household have lead in their drinking water above the 15 parts per million that is the federal Safe Drinking Water standard. So where is the lead coming from?

The lead in drinking water is predominately coming from the pipes. Lead in drinking water is most likely to occur in homes built before the mid-1950s when the water service lines delivering water from the water main in the street into each home were commonly made of lead. Lead was also used to solder copper pipes together before 1988. Also until very recently (after implementation of the 2011 Reduction of Lead in Drinking Water Act) almost all drinking water fixtures were made from brass containing up to 8% lead, even if they carry a plated veneer of chrome, nickel or brushed aluminum. So even a home like mine built with PVC piping in the 2000’s has some lead in most of the faucets.

Over time older pipes and fixtures corrode or simply wear away and the lead and other corrosion material (like rust) is carried to the drinking water. Time and water do cause corrosion, but this can be aggravated by the pH of the water or other changes in water chemistry. The amount of lead corroded from metal plumbing generally increases as water corrosiveness, a factor of the water’s acidity and calcium carbonate content, increases. In general, acidic water that has a pH less than 7 and that is low in calcium carbonate is more corrosive than water that has a pH higher than 7 and that is high in calcium carbonate. Soft water (low in dissolved solids like calcium and magnesium) tends to be more corrosive than hard water (with high concentrations of calcium and magnesium), and warm water is more corrosive than cold water. The common practice of grounding electrical connections to water pipes also can increase lead corrosion in the pipes.

In addition, water that sits for several hours or overnight in a pipe or brass fixture can leach lead from the brass faucet interior which may produce high lead levels in the first draw of drinking water. Though faucets purchased after 1997 contain less lead than previously used, they still can leach some lead -as evidenced by the detectible but extremely low “first draw” lead levels I find each year in my own plumbing. The most recent legislation, the 2011 Reduction of Lead in Drinking Water Act also called “Get the Lead Out,” mandates that after January 4, 2014, all faucets sold in the United States will contain no more than a weighted average of 0.25% lead in relation to wetted surface and can be labeled “lead free.”.

Lead can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body. The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lowered IQ in children. If your home was built before 1990 the only way to know if you have lead in your drinking water is to test.

The U. S. EPA limit for lead in drinking water is 15 parts per billion (ppb), but only requires action if limited sample monitoring for lead has not exceeded the 15 ppb action level in more than 10% of the homes tested. Cities are only required to test a very small number of homes monthly and the condition and age of the plumbing in the home really determines if lead levels will be elevated. You need to test your own home.

The true prevalence of lead in public water supplies at the tap is difficult to know because it depends on how corrosive the source water is, whether lead distribution lines are used, and whether a particular building contains leaded plumbing materials. Lead may also originate from the corrosion of brass fittings on certain types of submersible pumps used in private groundwater wells through the mid 1990's.

If you have elevated levels of lead in your home’s water you need to take action to reduce any potential exposure.
  • Replace the entire lead water service pipe. Typically water service lines a partially owned by the municipality and the portion on private property is owned by the homeowner. In Fairfax County homeowners are responsible for the entire service line from the water main. Replacing only a portion of the service line may actually make the problem worse. 
  • Replace the leaded components in the plumbing system with newer, non-leaded components. This usually requires replacing copper pipes and lead solder with plastic PVC or PEX pipes. 
  • Install an end-of-tap water filter. Look for filters certified by the National Sanitation Foundation for lead removal and reduction. Install this filter on the tap you use most often for cooking or for water to drink. Be aware that these small units are limited in the amount of time that the filter is effective in removing lead. Reverse osmosis units and activated alumina filters are very effective in removing lead once it is in the water. These units typically are attached to the kitchen tap and treat only the water from that tap.

Thursday, March 24, 2016

Controlling Mosquitos in Your Yard

Mosquito bites can be more than just annoying and itchy. They can carry viruses and make you very sick or potentially cause birth defects in the unborn children of pregnant women. Zika, Chikungunya , West Nile, Dengue, and St. Louis encephalitis are all viruses carried by mosquitoes and except for Zika have all occurred in the mainland United States. It is only a matter of time before the next virus Zika arrives. Mosquitoes become infected when they bite someone already infected with the virus. Infected mosquitoes can then spread the virus to other people. The major mosquito borne diseases are not common in the continental United States; however, Puerto Rico and the U.S. Virgin Islands have had large outbreaks.

We are fortunate that mosquitos die off or are dormant in the United States during the winter. So we have an opportunity to eliminate mosquito breading grounds ahead of the anticipate arrival of Zika and to protect us from West Nile Virus. The best way to prevent the Zika virus and the other mosquito borne viruses is to prevent mosquito bites in the first place. Management of adult populations for the Asian Tiger mosquito, Aedes albopictus, the carrier of the West Nile Virus and potentially the Zika virus is potentially more complicated than for other species due to tolerance to the insecticides malathion, temephos and bediocarb limiting the pesticides that can be sprayed on the adult populations. According to various mosquito studies the elimination of mosquito breeding habitat is the best approach to limiting the adult population for all species.

Mosquitoes lay their eggs in warm, still water. An adult female needs a blood meal to complete her life cycle and lay eggs. Often that blood meal comes from a human or other mammal. According to a study done by Dame and Fasulo in 2003, removing mosquito breeding habitat- any still water even as small as a bottle cap, can be an effective method for mosquito control.

Getting rid of mosquito breeding sites gets rid of mosquitoes. Eliminate any standing water on your property, change pet watering dishes, overflow dishes for potted plants, and bird bath water frequently. Do not allow water to accumulate in tires, flower pots, buckets, rain barrels, gutters, folds of tarps, trash, cups, bottle caps, wheel barrels, poorly drained areas, etc. Mosquitoes need only a bottle cap of water to breed. Most known types of mosquitoes do not travel far from where they hatch, so the actions of you and your neighbors can have a dramatic impact on your neighborhood mosquito populations. Check out the Maryland Department of Agriculture U-tube primer on eliminating the breeding ground for the Asian Tiger mosquito.

Because not all breeding sites can be eliminated, it may be necessary to use pesticides to kill the mosquito lava and the adult mosquito. Larvicieds, which kill mosquito larvae have been found to be more effective than adult spraying. The biological pesticide Bti (Bacillus thuringiensis var.israelensis) is commonly used in such places as storm drains and sewer treatment plants. Bacillus sphaericus works best in organically rich water in drains. Bti is proven to be effective and has low levels of toxicity to humans and wildlife.

By the time the larvae have moved into the third and fourth stage of metamorphosis, the Bti is less than 60 % effective, and additional larvicides may be necessary to eliminate the mosquito larvae. Methoprene (Altosid) may be necessary to kill larvae and prevent the use of pesticides aimed at adult mosquitos. Bti lasts approximately 30 days or longer if dry applied in heavier doses, and Methoprene lasts about 150 days. However, some studies find that Methoprene acts as an endocrine disruptor and causes deformities in wildlife.

Spraying using pesticides targeting adult mosquito populations is the least effective method of control and potentially the most damaging to human and animal populations. This type of spraying should only be done after carefully evaluating the effectiveness of the prevention strategies and the likelihood of pesticide-related illnesses and the contributing factors to a human epidemic of mosquito borne diseases.

Always choose the least dangerous pesticides. In general, synthetic pyrethroids have lower human health and environmental risks than organophosphates. Synthetic pyrethroids are pesticides derived from naturally occurring pyrethrins, taken from pyrethrum of dried Chrysanthemum flowers. They are designed to be more toxic with lower break down times than the naturally occurring pyrethrins. Though claimed to be selectively toxic to insects, synthetic pyrethroids are toxic to aquatic organisms, including fish in concentrations similar to those used for controlling mosquito. Many pyrethroids have been linked to the disruption of the endocrine system, reproduction and sexual development, interference with the immune system and the induction of breast cancer. The widespread use of pyrethroids can pollute water resources and affect non-target organisms and humans.

from Maryland Department of Agriculture

Remember that pesticides are only one part of a comprehensive mosquito management plan. Adult tiger mosquitoes are medium sized, black in color with distinctive white stripes. Tiger mosquitoes are persistent, moderately aggressive biters. The bite of the tiger mosquito is not painful and often goes unnoticed. Interrupted feeding is common and a female mosquito may bite the same person several times or move from person to person before the urge to bloodfeed is satiated. Tigers have a short flight range, about 100-200 yards. Tiger mosquitoes tend to remain near ground level in shaded areas, under decks and shrubs, basement stairswells and crawl spaces. The most effective way to prevent and control mosquito-borne disease is an integrated mosquito management program, and should include:
  • reduction of mosquito breeding sites,
  • surveillance and monitoring levels of mosquito activity, and where virus transmission is occurring,
  • use of pesticides to control both mosquito larvae and adult mosquitoes when found to be necessary, and
  • outreach and public education
In addition, use personal protection to avoid mosquito bites. Long pants, long sleeves and insect repellent such as DEET will reduce exposure to bites. The Asian tiger mosquito is a day biter that prefers legs and with feeding peaks early morning and late afternoon, so by limiting outdoor activities at dawn and dusk when mosquitoes are generally most active, bites can be avoided. The CDC also recommends staying inside as much as possible in places with air conditioning or that use window and door screens to keep mosquitoes outside.

Monday, March 21, 2016

The Sweet Smell of Chlorine

On March 7th Fairfax Water and the Arlington Department of Environmental Services began flushing their water distribution systems. Each spring Fairfax Water and Arlington DES flushes its water mains by opening fire hydrants and allowing them to flow freely for a short period of time. In addition, the Washington Aqueduct and Fairfax Water temporary change how the water is disinfected.

For most of the year, chloramines, also known as combined chlorine, is added to the water as the primary disinfectant. During the spring the water treatment plants switch back to chlorine in an uncombined state, commonly referred to as free chlorine. This free chlorine reacts with sediments suspended during flushing and kills bacteria that may be in the bio-film that forms on the pipe walls. Many water chemistry experts believe this short exposure to a different type of disinfectant maintains a low microbial growth in the bio-film and improves the quality and safety of the water.

This change in disinfection is an annual program to clean the water distribution pipes and maintain high water quality throughout the year. The U.S. Army Corps of Engineers Washington Aqueduct provides water to the District of Columbia, Arlington County, and other areas in Virginia. Fairfax Water provides water to Fairfax county and parts of both Loudoun and Prince William County. Both Fairfax Water and the Aqueduct switch from chloramine to chlorine during this period that runs from March 7th to May 2nd at the Aqueduct and into June for Fairfax Water.

You may notice a slight chlorine taste and smell in your drinking water during this time, this is not harmful and the water remains safe to drink. If you are a coffee and tea lover like me, use filtered water or leave an open container of water in the refrigerator for a couple of hours to allow the smell to dissipate. Water customers who normally take special precautions to remove chloramine from tap water, such as dialysis centers, medical facilities and aquarium owners, should continue to take the same precautions during the temporary switch to chlorine. Most methods for removing chloramine from tap water are effective in removing chlorine. The annual chlorination is important step to remove residue from the water distribution system.

Flushing the water system entails sending a rapid flow of chlorinated water through the water mains. As part of the flushing program, fire hydrants are checked and operated in a coordinated pattern to help ensure their operation and adequate flushing of the system. The flushing removes sediments made up of minerals which have accumulated over time in the pipes as well as bacteria on the bio-film. An annual flushing program helps to keep fresh and clear water throughout the distribution system. Removing the residue ensures that when the water arrives in your home, it is the same high quality as when it left the water treatment plant.

Drinking water in Fairfax comes from either the Potomac River or Occoquan Reservoir. The Washington Aqueduct draws its raw water from the Potomac. This water needs to be treated to remove impurities and disinfected to kill disease causing germs such as Salmonella, Campylobacter, and norovirus. Giant screens on the water intake pipes prevent trash, debris and fish, but the water is only screened and not yet drinkable. In the water treatment plant potassium permanganate (KMnO4) is added to the water to control taste and odors, remove color, prevent biological growth within the water treatment plant, and remove iron and manganese which are naturally occurring predominantly nuisance contaminants.

Then water is pumped into a series of water chambers where the pH is adjusted by adding either caustic soda or sulfuric acid and a coagulant to remove small particles of dirt suspended in the water. The water moves through a series of mixing chambers with progressively slower mixing to allow the particles to coagulate into larger and larger particles until dirt floc is formed. Then the water is held in sedimentation basins and the floc is allowed to settle to the bottom of basins by gravity where they are removed.

The next step in the water treatment process in Fairfax is the infusing of the water with ozone gas and the first of two disinfection steps. This step is not used in every water treatment plant. Ozone is highly effective in eliminating the Cryptosporidium bacteria and other naturally occurring microorganisms present in water. Unlike ultraviolet and chlorine disinfection systems (which are still used in many locations), there is no re-growth of microbes after ozonation. Ozonation also reduces the formation of trihalomethanes (chlorine breakdown products) because of the reduction of organic materials in the water before chlorination.

The final steps in the water treatment process is the second disinfection, fluoridation and the addition of a ammonium hydroxide to adjust the pH slightly to prevent corrosion of piping and fixtures of the plumbing systems in customer homes to prevent the leaching of lead from older plumbing systems and old connector lines into water. For most of the year Fairfax Water and the Washington Aqueduct use chloramine as the final disinfection step in water treatment. However, during the spring of every year they use chlorine to disinfect and flush the delivery network. Free chlorine is better suited to remove residue that may have collected in the pipes and a coordinated opening of fire hydrants serves to flush the system.

Thursday, March 17, 2016

Genetically Modified Mosquito Field Test

On Monday, the Food and Drug Administration (FDA) released for public comment a draft Environmental Assessment (EA) submitted by Oxitec, Ltd., that assesses the potential environmental impacts of a field trial of the company’s genetically engineered (GE) Aedes aegypti mosquitoes (OX513A) in Key Haven, Florida. Aedes aegypti is known to transmit human viral diseases, including Zika, dengue, yellow fever and chikungunya and is an invasive species of mosquito that has taken of residence in Florida and parts of the south.

After a long period of review, last week the FDA announced a preliminary finding that there would be no significant impact on the environment (FONSI) if Oxitec and Key Haven, Florida proceeded with a field trial of Oxitec’s genetically engineered mosquito in the Florida Keys after a public comment period and a review of the public comments. According to the FDA announcement, the preliminary FONSI is based on FDA’s review of the draft Environmental Assessment and other data, observations made by FDA inspectors and CDC expert during an inspection of the company site, and a visit to the proposed field study site. The FDA worked with the U.S. Environmental Protection Agency (EPA) and the Center for Disease Control and Prevention (CDC) to review the application by Oxitec.

Aedes aegypti mosquitoes are a non-native species in the USA. They can spread serious diseases such as dengue fever and chikungunya and are a known carrier of Zika. Dengue fever and chikungunya are currently not an active health threat in the Florida Keys because the Florida Keys Mosquito Control District has been working hard to reduce the Aedes aegypti population, but spraying of mosquitos has only limited success in controlling the population.

Using advanced genetics and molecular biology Oxitec has developed a genetically modified mosquito, Aedes aegypti that is designed to control the Aedes aegypti mosquito population. Oxitec has used genetic modification to create male insects which seek out and mate with females. After an Oxitec mosquito has successfully mated with a wild female, any offspring that result will not survive to adulthood, so the mosquito population declines.

This approach is targeted at a single species, unlike conventional insecticides or pesticides which kill insects indiscriminately. According to the company, this is more effective and is much better for the environment than pesticide spraying. In the field trial the Oxitec modified mosquitoes will be released and monitored in an area of the Florida Keys over a predetermined and sustained period of time. Open field trials of the OX513A genetically engineered mosquito have been conducted in Brazil, the Cayman Islands, Panama, and Malaysia.

OX513A mosquitoes have been genetically engineered to encode a conditional or repressible lethality trait, which is a function of the overexpression of the tetracycline-repressible transactivator (tTAV) protein, and a red fluorescent marker protein. When tetracycline is not present, tTAV causes lethality in the offspring of mating between OX513A males and wild-type females. The fluorescent marker is used to identify the genetically modified mosquitos.

The plan is Oxitec to produce genetically modified mosquito eggs in Oxford, UK and ship them to Marathon, FL for rearing and ultimately release in the proposed field trial. The goals of the proposed investigational trial are to evaluate the breeding of the OX513A mosquitoes with local wild-type Aedes aegypti females, to assess the survival of their offspring, and to estimate the suppression of the overall Aedes aegypti population at the trial site relative to an untreated comparison area. At the conclusion of the investigational field trial, the OX513A mosquitoes would die off at the end of their natural lifetimes in the environment (approximately two days) and wild-type Aedes aegypti levels are expected to recover to pre-trial numbers.

To submit your comments electronically to the docket, go to and type FDA-2014-N-2235 in the search box. The Environmental Assessment can be read at this link and the FDA finding of no significant impact here.

Monday, March 14, 2016

Hexavalent Chromium and Possum Point

When Dominion Power agreed last week to provide enhanced monitoring and protection for Quantico Creek and the Potomac River from the dewatering of the coal ash ponds at Dominion’s Possum Point Power Station they promised to perform enhanced monitoring for arsenic, selenium, lead, copper, antimony, and thallium. They did not mention hexavalent chromium. The reason is that hexavalent chromium is not regulated in Virginia or on a federal level. In September, 2010, EPA released a draft of the scientific human health assessment (Toxicological Review of Hexavalent Chromium) for public comment and external peer review, but has yet to finish the review, water issues are lower on their priority list.

Only a small fraction of the 80,000-100,000 potential drinking water contaminants are regulated. The EPA only regulates chemicals that are found to be prevalent in large water systems, are dangerous to public health and can be cost effectively removed. Currently, the EPA is analyzing data collected in its UCMR3 national drinking water monitoring program during 2013-2015 to understand the prevalence of chromium and hexavalent chromium exposure in large drinking water systems in the United States. However, hexavalent chromium is more likely to occur in groundwater and is quite persistent. Though hexavalent chromium can occur naturally, there are locations where chromium compounds have been released to the environment and groundwater in particular through leakage of waste storage ponds and improper industrial disposal practices.

Though Possum Point is downstream from nearby drinking water supplies; however, the current level of impact needs to be investigated and monitored for the 24 nearby private wells. Dominion’s enhanced monitoring should include testing of groundwater and the 24 nearby drinking water wells for hexavalent chromium to determine the extent of impact if any from the decades storage of the coal ash on site. The Prince William County Health District is taking the lead in providing water analysis for those homeowners and should include analysis for hexavalent chromium. There has been no testing of the 24 nearby drinking water wells for hexavalent chromium, but hexavalent chromium can be measured at levels as low as 0.02 ug/L by ion chromatography using a modified version of EPA Method 218.6 or EPA Method 218.7. However, at this time the homeowner will have to bear the cost of the analysis.

The owners of those nearby wells should contact the Department of Health and remember Hinkely, California located in the Mojave Desert. The groundwater in Hinkley became contaminated with hexavalent chromium from the compressor plant operated by Pacific Gas and Electric (PG&E). You may have heard of Hinkely or hexavalent chromium because of the movie “Erin Brockovich.”

In 1993, a legal clerk named Erin Brockovich investigated an elevated cluster of cancer in Hinkley that were linked to hexavalent chromium. Average hexavalent chromium levels in Hinkley were recorded as 1.19 parts per billion (ppb) with an estimated peak of 20 ppb. The PG&E Compressor Station averaged 7.8 ppb and peaks at 31.8 ppb based on the PG&E Background Study.

Though the U.S. Environmental Protection Agency (EPA) regulatory limit of total chromium at 100 ppb, and the EPA does not regulate hexavalent chromium at this time, it would be a tragedy not to verify that the nearby drinking water wells have not been impacted by the decades of coal ash storage at Possum Point. The California maximum contaminant level (MCL) for hexavalent chromium was lowered in 2014 to 0.01 ppb in drinking water. Hexavalent chromium in drinking water is not regulated in Virginia, only total chromium.

Chromium is an element that is found naturally in coal in what is called the trivalent oxidation state, Cr(III). Chromium exists in nature as either a component in clay minerals such as illite or chlorite, or as its oxidized components; small-particle chromium oxide (Cr2O3) or oxyhydroxide (CrOOH) carbonaceous components of coal, or more rarely as chromite (FeCr2O4), as a result of special geology. Chromium is a metallic element found in rocks, soils, plants, and animals.

Cr(III) is relatively non-hazardous to humans and is in fact an essential nutrient. Chromium in coal is not considered a serious health risk. However, during commercial coal combustion, coal is burned with excess air to raise heat to generate steam for turbines that produce electricity. In the process, significant quantities of ash are created from the incombustible inorganic components in coal. That ash can contain not only hexavalent chromium, but also arsenic, selenium, lead, copper, antimony, and thallium. Furthermore, there is the potential for greatly increasing the health risk associated with chromium because not only can its concentration in the ash be increased by up to 10 times compared to that in the original coal, but Cr(III) can also be oxidized during coal combustion to form Cr(VI), which poses a much greater threat to public health.

Hexavalent chromium is commonly referred to as: chromium 6, chromium VI, Cr(VI), Cr+6, or hex chrome. Hexavalent chromium in the form of chromates is very soluble and, because of the six available electrons it has a high oxidizing capability, and can have severe adverse effects on the human body, including cancerous tumor formation and gene damage. Research by the National Toxicology Program (NTP) has found that hexavalent chromium causes cancer in laboratory animals following oral ingestion at high doses (NTP, 2008). California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) analyzed data collected from China that found increased rates of stomach cancer in people who were exposed to very high levels of hexavalent chromium in drinking water (OEHHA, 2010).

Hexavalent chromium can be measured at levels as low as 0.02 ug/L by ion chromatography using a modified version of EPA Method 218.6 or EPA Method 218.7. Though I believe that Dominion Power should pay for the analysis, and the Prince William Health District should test to make sure that all residents of Prince William County have groundwater that is safe to drink, test your well for piece of mind.

Thursday, March 10, 2016

Possum Point Agreement

On Tuesday Dominion Power agreed to terms with the Prince William County Board of Supervisors to provide enhanced monitoring and protection for Quantico Creek and the Potomac River from the dewatering of the coal ash ponds at Dominion’s Possum Point Power Station.

If you recall, Dominion Power has been moving forward with a plan to “close in place” 3.7 million cubic yards of coal ash under the recently finalized U.S. EPA Coal Ash regulation. The plan for Possum Point is to consolidate all of the on-site coal ash into one impoundment. There is estimated to be 3.7 million cubic yards of coal ash. Dominion has collected more than 1 million cubic yards of ash from four smaller ponds, put them in a 120-acre pond that already contains 2.6 million cubic yards of coal ash that they have begun to dewater. Ultimately, the pond will be capped with an impermeable membrane to prevent future infiltration of rain.

These coal ash ponds have been open to the elements and taking on water for decades. Trace contaminants and metals in the coal ash may have already leached into the groundwater, Quantico Creek and Potomac. The State Water Control Board and Virginia Department of Environmental Quality (DEQ) are the regulating agencies that oversee the dewatering of the ponds, though the U.S. EPA maintains authority to review applications and permits for "major" discharges, a distinction based on discharge quantity and content. In January 2016 DEQ and the Water Control Board approved the modifications to Dominion’s Virginia Pollutant Discharge Elimination System (VPDES) Permit allowing the treatment and subsequent discharge of the coal ash waters to Quantico Creek, which flows into the Potomac River.

Several groups including the Prince William County Board of Supervisors had raised concerns with the plan and the speed with which they are proceeding without community involvement and input. In addition to the County Board of Supervisors the state of Maryland, the Southern Environmental Law Center and the Potomac Riverkeeper Network have raised issues about the level of treatment of the water being released to dewater the pounds and the Riverkeepers contend that the large pond where they are consolidating all the coal ash is only partially lined.

Now, the Prince William County Board of Supervisors has agreed to withdraw its appeal of the permit, and Dominion has agreed to steps that go beyond the VPDES Permit requirements. This agreement between Dominion Power and the Board of Supervisors focuses on reduced contaminant levels in the discharged water and independent testing of the levels:

​Dominion agrees to provide advanced treatment of all water from the coal ash ponds prior to discharge, regardless of whether this treatment level is needed to meet the required VPDES Permit levels.
  • Dominion agrees to take additional hourly samples. If any sample exceed triggers for certain elements (arsenic, selenium, lead, copper, antimony, and thallium), Dominion will provide an additional enhanced treatment step.
  • Dominion will only use a State accredited third-party independent laboratory for its VPDES Permit-required sampling and testing.
  • Dominion will implement Standard Operating Procedures and Quality Assurance/Quality Control protocols. 
  • Dominion will regularly post on a publicly accessible website all permit-required test results for public review.
  • Dominion and the County will work collaboratively to coordinate on solid waste permitting during the next phase of the closure of the coal ash ponds to ensure that the Board’s and Dominion’s commitments to groundwater quality and environmental protection continue to be met.
  • Dominion will reimburse the County for its costs of outside technical consultation services. 
This agreement is  much more in the spirit of the finalized EPA regulation for coal ash that requires that coal ash disposal site must have protective liners to prevent groundwater contamination. The rule also requires companies to conduct monitoring of disposal sites, clean up any existing contamination, and close and remediate unlined disposal sites that have polluted groundwater. Finally, monitoring data, corrective action reports, and other important information about the site must be made available to the public. I believe that additional site characterization should take place.

Possum Point Power Station is located in Dumfries Virginia in the eastern part of Prince William County that borders the Potomac River and the Quantico Creek. Dominion Virginia Power has not burned coal at Possum Point for 13 years and is unlikely to burn coal to generate power in the future. Possum Point is downstream from nearby drinking water supplies and is unlikely to impact local residents beyond what has already taken place over the decades.

Dominion’s closure plan should include additional site investigation to demonstrate to the stakeholders in the community that the liner in coal ash Pond D is sound. In addition it is essential that testing of groundwater, surface water sediments, and the water treated at the outfalls be done for a broader spectrum of contaminants to include hexavalent chromium to better protect the environment and determine the extent of impact if any from the decades storage of the coal ash on site. Though Possum Point is downstream from nearby drinking water supplies and is unlikely to impact local residents beyond what has already taken place over the decades; the current level of impact needs to be investigated and monitored for the 24 nearby private wells.

Closing the coal ash on site when properly done is probably the best solution. A safe closure requires ongoing monitoring and maintenance that is best accomplished at an operating and regulated plant rather than at a remote cap and leave it location. All physical barriers fail over time this is addressed by monitoring and maintaining the systems.

Monday, March 7, 2016

Zika Research Update

The Zika Virus is spread to people through mosquito bites, currently from the Aedes species mosquitoes. There have also been documented cases of Zika Virus spreading through seamen and passing through the placenta. There is no vaccine to prevent or medicine to treat Zika. Outbreaks of Zika have occurred in areas of Africa, Southeast Asia, the Pacific Islands, and the Americas.

As of February 24, 2016 the Center for Disease Control and Prevention reports that there have been 107 cases of Zika within the United States, all of them were travel associated (including the one that was sexually transmitted). In addition, in the U.S. Territories of Puerto Rico, American Samoa and the US Virgin Islands there have been 39 cases of locally acquired Zika virus and 1 case of travel associated Zika Virus.

The disease symptoms which include fever, rash, joint pain, myalgia, headache, pain behind the eyes and conjunctivitis (pink eye) are usually mild and last for 2 to 7 days. Infection may go unrecognized or are misdiagnosed as dengue, chikungunya or other viral infections that cause fever and rash. Many do not even know they have Zika, according to the CDC only 20% of people infected with Zika virus will develop symptoms.

The concern of course is the possible association of Zika Virus with a serious birth defect, microcephaly, babies born with abnormally underdeveloped heads, and other poor pregnancy outcomes in babies of mothers who were infected with Zika virus while pregnant. In addition to an observed connection to other neurological disorders. Several months after the introduction of the Zika virus into Brazil, there was an increase in the occurrence of congenital microcephaly by twenty times.Two recent studies have strengthened this connection. The first study was a tissue and cell bench study that showed that the Zika virus selectively damaged the cells necessary to develop the brain's cortex, killing the cells and preventing the development of new brain cells .Read the study here.

Published in the New England Journal of Medicine, the second study looked at the 88 women at one medical clinic in Brazil.The clinic tested pregnant women who came to the clinic with fever and a rash a for the Zika virus. Of the women who tested positive for the Zika virus and had additional followup (several of the women declined further testing), 29%  suffered a series of negative outcomes including  fetal death, tiny heads, shrunken placentas and nerve damage including blindness. Besides the high percentage of babies effected, it also did not matter which trimester of pregnancy the mother was in when she became infected with the Zika virus. A much larger study involving 5,000 women is due out by summer.

The CDC is working with international partners to study infants with microcephaly to identify what role various factors, including Zika virus, may play in this birth defect and is closing in on Zika Virus as a factor of the birth defect. Since November 2015, CDC has been developing methods for testing for the Zika in tissue samples. In December 2015, tissues samples from two newborns (born at 36 and 38 weeks gestation) with microcephaly who died within 20 hours of birth and two miscarriages (at 11 and 13 weeks) were submitted to CDC, from Brazil, for testing for suspected Zika virus infection.

All four mothers had clinical signs of Zika virus infection, including fever and rash, during the first trimester of pregnancy, but did not have clinical signs of active infection at the time of delivery or miscarriage.. Samples included brain and other autopsy tissues from the two newborns, a placenta from one of the newborns, and products of conception from the two miscarriages. The studies showed the presence of Zika virus in the brains of infants born with microcephaly and in placental tissues from early miscarriages. This testing has been the best evidence to date of the connection of the Zika virus to microcephaly.

Several media reports in last month suggested that a pesticide called pyriproxyfen might be linked with microcephaly. These media reports appear to be based on a February 3, 2016 publication authored by an Argentine physicians organization, which claims that the use of pyriproxyfen in drinking water in Brazil is responsible for the country’s increase in microcephaly cases. Pyriproxyfen is a larvacide widely used to control the spread of disease causing mosquitos.

The World Health Organization has approved the use of pyriproxyfen for the control of disease-carrying mosquitos. Pyriproxyfen is a registered pesticide in Brazil and other countries, it has been used for decades, and it has not been linked with microcephaly. In addition, exposure to pyriproxyfen would not explain recent study results showing the presence of Zika virus in the brains of infants born with microcephaly. The CDC is dismissing the reports of pyriproxyfen association with the frightening increasing in microcephaly cases as non-causal.

Microcephaly can happen for many reasons, including genetics, maternal infections, and being close to or touching toxins during pregnancy. Results of recent epidemiologic and laboratory studies discussed above performed in Brazil and the United States strongly support, but don’t yet prove, the link between Zika virus infection during pregnancy and microcephaly. Nonetheless, we need to worry about the spread of the Zika virus to the United States.

The Zika Virus will spread in the United Stated to people who have not traveled by a mosquito drawing blood from an infected individual incubating the virus and then spreading it to others; also, it is confirmed that the Zika virus can spread through sexual contact.. Infected mosquitoes will travel in cargo and planes will carry the Zika virus north. Infected people will carry the disease north and it will spread through our mosquito populations. Our own Asian Tiger Mosquito, Aedes albopictus, is a cousin to the mosquito carryin the Zika virus in Brazil, South and Central America.

The Asian Tiger mosquito entered the United States in shipments from northern Asia in the mid-1980s. It can survive in a broad range of climates and has spread rapidly from the point of first detection in the south-central United States to the entire eastern and central U.S. and now California. Reanalysis of the mosquitoes captured in a 2007 mosquito study in Africa identified the presence of the Zika virus in the Asian Tiger mosquito. Thus, this insect, known to be the vector of dengue and chikungunya, also can carry the Zika virus. The good news for us is so far the winter die off in the more northern states has limited the populations of the mosquito and the diseases that the Asian Tiger mosquito can spread. We need to begin preparations for the summer mosquito season. .

Thursday, March 3, 2016

2016 Water Clinic for Prince William and Loudoun Counties -Get Your Well Tested

The Virginia Cooperative Extension (VCE) Office will be holding its annual drinking water clinic for well owners in Prince William and Loudoun Counties as part of the Virginia Household Water Quality Program. The Prince William VCE welcomes our well, spring and cistern owners in Prince William, Loudoun, Fairfax, and Fauquier (and anyone else in Virginia willing to drive to the clinic to join us) because it is a statewide grant from USDA Cooperative State Research, Extension and Education Service that allow Virginia to hold and subsidize the analysis cost of the analysis for the water clinics. To sign up for the program please call 703-792-7747 or email Please register as soon as possible so that the Prince William VCE can order enough test kits.

The program consists of two meetings- one to get instructions and pick up test kits, and the other a month later to get results and provide interpretation and recommendations. Samples will need to be dropped off at the VCE Prince William Office for analysis a day and a half after the first meeting. The samples will be analyzed for 14 chemical and bacteriological contaminants and the cost this year is only $55. Comparable analysis at a private commercial lab would cost $150-$200. Samples will be analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria.

The Kickoff Meeting will be on March 28, 2016 at 7 - 8:30 pm at the Old Courthouse, 9248 Lee Avenue in Manassas, VA 20110
A brief presentation will be given to discuss common water quality issues in your area and instructions for how to properly collect the water samples from your tap. Water sampling kits will be distributed with written sampling directions and a short survey about your water supply for data gathering purposes. Checks (or money orders) for $55 to cover the cost for the analysis and sampling kits will be collected. A friend or neighbor may drop off your check and pick up your sampling kit.

The samples should be taken early Wednesday morning and then dropped off on Wednesday March 30, 2016, between 6:30am and 10am at the VCE Prince William Office, at 8033 Ashton, Suite 105, Manassas 20109

Results Interpretation Meeting will be held on May 11, 2016 at 7 pm once more at the Old Courthouse 9248 Lee Avenue, Manassas, VA 20110
Participants will receive their confidential water test results. A presentation will be given that explains what the numbers on the test report mean and what possible options participants may consider to deal with water problems. Experts will be on hand to answer any specific questions you may have about your water and water system. I will be one of volunteers present to help with the program. Come join us.

Just because your water appears clear doesn’t necessarily mean it is safe to drink. All drinking water wells should be tested at least annually for at least Coliform bacteria and E Coli. Testing is the only way to detect contamination in your water and last year I found that I needed to disinfect my own well. Testing is not mandatory, but should be done to ensure your family’s safety. The Virginia Private Well Regulations only specify construction requirements. There are no requirements for maintenance or water testing after a well is approved. Maintenance and ensuring that water is safe to drink is the responsibility of the owner.

The goal of the Virginia Household Water Quality Program is to educate well owners, improve the water quality and protect the health of Virginians with private water supplies, such as wells, springs and cisterns. This all begins with testing and understanding your water and properly maintaining your water system. In 60 of Virginia’s 95 counties more than half the households rely on private wells, springs, and cisterns. In total there are more than 1,500,000 households in Virginia with private water supplies. Homeowners relying on private water supplies are responsible for all aspects of their water system’s management. All wells should be routinely tested every year or so. If there is a pregnant woman or infant in the home the water should be tested. If there is any change in the taste, appearance, odor of water or your system is serviced or repaired then water should be tested to confirm that no contaminants were introduced.

Most of the water quality issues with private wells are from naturally occurring contamination or impurities. While many natural contaminants such as iron, sulfate, and manganese are not considered serious health hazards, they can give drinking water an unpleasant taste, odor, or color and be annoying and persistent problems and EPA has established secondary standards that can be used as guidance. Excessive levels of sodium, total dissolved solids, harness, can be an annoyance and impact appliances. Several of the naturally occurring contaminants that commonly appear in well water are primary contaminants under the Safe Drinking Water Act and can be a health hazard- nitrate, lead, arsenic, floride, and copper. The VCE Drinking Water Clinic will test for these.

In addition running the drinking water clinics VCE has established the Virginia Master Well Owner Network (VAMWON), a group of Virginia Cooperative Extension educator/agents and screened volunteers trained in proper well construction and location, appropriate maintenance and protection of wells and springs, interpretation of water tests, and water treatment options. These educator/agents and volunteers form an excellent resource base for homeowners. If you are a private water system owner, consider contacting a Master Well Owner in your area if you cannot join us for the water clinic.