What Health Risks Does Climate Change Pose?

Patient Presentation
A 9-month-old male came to clinic for his health supervision visit. His parents were graduate students at the local university and would be returning to live in China in 2 weeks. They were wondering about vaccines particularly for Japanese encephalitis because they would be living in a high risk area in China. The past medical history was unremarkable. The pertinent physical exam showed normal vital signs with growth parameters between 10-25% for height and weight and 50% for head circumference. The examination was otherwise unremarkable.

The diagnosis of a healthy male was made. The pediatrician discussed the options of starting the Japanese encephalitis vaccine in the U.S. and finishing it in China or waiting until they went to China to do the complete series there. “Japanese Encephalitis virus is more common during the warmer months, but I don’t know with the extent of climate change, if the risky time period has been extended,” the pediatrician said. Reviewing some governmental information with the parents on the computer in the room, the pediatrician was able to find out that there had been extension of the risk areas and time periods in East Asia. As it was April and the risk would be increasing, and after more discussion, the family decided to do the first Japanese Encephalitis vaccine in the U.S. and then followup with the second one once they were in China. The family felt good as this was similar to the routine Chinese vaccine schedule for infants also.

Japanese encephalitis virus (JEV) is a Flavivirae, arbovirus that is endemic to many areas of Asia and the Pacific. It is estimated to affect ~70,000 people/year with ~10-15,000 deaths yearly in 20 countries, with a fatality rate of 35-40%. It can cause encephalitis and irreversible neurological morbidity. JEV is spread by Culex mosquitos which feed on swine. Increased environmental temperature and increased humidity (warm air is more moist) increases mosquito numbers, their survivability and ultimate dissemination. China has the highest rates of JEV with particular areas being more prone, as some areas co-farm rice and swine and the families live closely to the rice paddies and livestock which encourages transmission. JEV’s range has expanded over the past few decades including in 2009 into Tibet which was thought to be immune because of its altitude. Similar geographic spread has been found in other countries too such as Australia. Mass immunization in China and other countries has decreased the disease but it still remains a threat.

Learning Point
Weather is a moment-to-moment, day-to-day event and differs from climate which occurs across seasons, many years, and regions. “Climatic conditions and weather patterns have many consequences for human physiology, health and survival. Some health impacts, as from extreme exposures such as heat waves, occur directly. However, most climate-related health risks are mediated via the influences of climatic changes and shorter term weather fluctuations on food yields, water flows, patterns of infectious disease and the movement or displacement of groups and populations. When climatic conditions change over time, then we should expect changes in patterns of health risks and in population health profiles.” Most climatic health issues are not due to direct affects, but are due to indirect effects on the environment, ecology and social impacts.

Climate change health conditions include:

  • Primary/direct health effects
    • Are from extreme events such as heat waves, floods, fires, hurricanes/typhoons, landslides, tornados, and storms. The intensity and frequency of these events obviously can affect more people more frequently.
    • Direct health impact includes injuries, hospitalizations, poisoning, death, and numerous mental health issues. Children are especially affected by mental health issues.
  • Secondary health effects
    • Air quality related problems such as allergies and asthma
      • Air pollutants (including ground level ozone changes) and aeroallergens can increase because of wildfires, rising temperatures, rainfall patterns and altered crop yields.
    • Food related problems which can affect food supply, quality and overall nutrition
      • Rainfall patterns and soil temperature affects crop and animal food yields
      • Increased contamination of food/water with bacteria or environmental pollutants (including sewage) making food/water unusable
    • Infectious disease patterns
      • Expansion of number, range and activity of host species or vector species increases the infectious disease risks
      • Examples include non-human hosts of rodents, bats and vector-born illnesses such as Dengue, Hantavirus, Japanese Encephalitis Virus, Leishmaniasis, Lyme disease, malaria, schistosomiasis, and others.
  • Tertiary health effects
    • Water changes including stocks and flows of reservoir water such as groundwater recharging and glaciers/snowpack
    • Sea water elevation can cause local changes in water quality (increased bacterial or environmental toxins) with decreased fishing, arable or grazing land.
  • Changes in food and water supplies and land availability can lead to increased epidemics, population stress, conflict, population displacement and deteriorating social structure
    • “Displacement typically entails increased risks to health from undernutrition, infectious diseases, conflict situations, mental health problems – and from changes in health related behaviors such as alcohol consumption, tobacco smoking and transactional sex.”

On the potential positive side, some climatic changes can benefit some regions such as cold-weather areas will have fewer strokes or myocardial infarctions due to winter weather. Temperate areas that become even warmer could have drier conditions and therefore fewer mosquito-borne infectious diseases as there is less water for breeding and decreased lifespan.

Questions for Further Discussion
1. What climate change health conditions have you seen locally?
2. What climate change health conditions could you expect in your local area?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Climate Change, Environmental Health, and International Health.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Kurane I. The effect of global warming on infectious diseases. Osong Public Health Res Perspect. 2010 Dec;1(1):4-9.

McMichael AJ, Lindgren E. Climate change: present and future risks to health, and necessary responses. J Intern Med. 2011 Nov;270(5):401-13.

Bai L, Morton LC, Liu Q. Climate change and mosquito-borne diseases in China: a review. Global Health. 2013 Mar 9;9:10.

Tian HY, Bi P, Cazelles B, Zhou S, et.al.. How environmental conditions impact mosquito ecology and Japanese encephalitis: an eco-epidemiological approach. Environ Int. 2015 Jun;79:17-24.

Ahdoot S, Pacheco SE; Council on Environmental Health. Global Climate Change and Children’s Health. Pediatrics. 2015 Nov;136(5):e1468-84.

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

Safety Risks of Baltic Amber Teething Necklaces and Similar Cultural Practices?

Patient Presentation
A 10-month-old female came to clinic with fever for 24 hours and pulling on her ears. She had had upper respiratory tract infection symptoms and was not sleeping well for 2 days. The past medical history was unremarkable.

The pertinent physical exam showed a slightly cranky but consolable female who was afebrile and had growth parameters in the 50-75%. HEENT showed bilateral bulging eardrums with loss of landmarks, erythema, and no movement with insufflation. She had an amber-colored teething necklace around her neck. Her lungs were clear and her skin showed no rashes. The rest of her examination was negative.

The diagnosis of a female with bilateral supprative otitis media was made and oral antibiotics were prescribed. The pediatrician asked the mother about the necklace. “It’s an amber teething necklace to help her with teething. She has a lot of drooling and I think this helps,” the mother said. The pediatrician discussed that the necklace posed a choking hazard. “Oh, she only has it on when she is awake and I can watch her,” the mother responded. “I understand that that is always your intention, but things can happen like her falling asleep and you forgetting to take it off,” he said, and added “We don’t recommend any jewelry for children because of the risks, but if you are going to use it, can it be pinned to the inside of the clothing still touching the skin, or even placed on an ankle where it is less likely for her to be strangled or for her to get a loose bead into her mouth?” The mother didn’t respond. At a routine health supervision visit, the child was still wearing the necklace on her neck. The pediatrician again tried to engage the mother about the potential risks and was told directly that the mother intended for the child to continue to wear it around her neck.

Amber is fossilized tree resin that is prized for its beautiful colors from deep brown to caramel, yellow, green or even white. It is promoted for its “healing properties” although there is not scientific evidence that supports the many potentiated mechanisms of these properties. One of the most consistent is that amber contains succinic acid which proponents believe is absorbed through the skin and is a pain reliever. Succinic acid was actually first purified from amber in 1546 by a German chemist. Succinic acid in humans is an important part of the Krebs cycle and acts as an important metabolite in several metabolic pathways including hypoxia, tumorigenesis, superoxide radicals and in inflammation. Elevated succinate occurs in various disease states including hypertension, inflammatory bowel disease and type 2 diabetes in animal models and bacteria. Even with increased amounts of succinic acid in an amber teething necklace, the amount that would be have to be released, then absorbed through the skin (which is difficult) and then make it through the circulatory system to potential mediators of dental inflammation is certainly not a therapeutic amount. Amber necklaces may not even be amber as plastic, glass, phenolic resins and copal are easily substituted and passed off as real amber. Real amber is relatively expensive and many items on the market that claim to be amber are not.

Teething occurs usually from 6-30 months with the eruption of 20 primary teeth. The individual tooth eruption occurs over ~7-8 days which includes the 4 days before and 3 days after the eruption. While many people attribute many symptoms to teething including fevers and diarrhea, there is not much evidence that supports these ideas. Some children will have some discomfort for a short amount of time around eruption and may have more drooling around this time. This is also a time period during the child’s life when many other childhood illnesses occur especially viral illnesses.

Recommended options for teething symptoms includes:

  • Gum massage with soft cloth or clean fingers
  • Chewing items that are chilled, not frozen as they are too hard. Rubber teething rings are one such item. All items, but especially plastic teething rings, should be cleaned following the manufacturer’s instructions. Plastic rings placed in boiling water or a dishwasher may lose their integrity.
  • Unsweetened teething biscuits or rusks for children > 6 months who are eating solid foods
  • Oral pain relievers such as acetaminophen or ibuprofen. Oral teething gels containing benzocaine are not recommended because of the risk for methemoglobinemia.
  • Drying saliva on the skin to prevent irritation

Learning Point
Because of the strangulation risk, in 2010, the Canadian federal public health department issued a consumer product safety warning. France and Switzerland also have banned sales of amber teething necklaces in their pharmacies.
A study from France, showed that even when families are given the information about amber necklaces risks, they often still continue the practice. “When informed of the danger of strangulation, numerous families preferred to continue this practice: their irrational fear of seeing their child suffer [while teething] surpassed their fear of the risk of strangulation[,]” the study concluded.

Risks for amber necklaces include:

  • Strangulation – manufacturing standards are lacking and therefore safety clasps may not be present or may not work
  • Choking hazards – beads or other necklace parts could be ingested and/or aspirated. Some believe that individual knotting between the beads only allows 1-2 beads to fall off if the necklace is broken, but even 1-2 beads can cause a choking hazard
  • Infectious disease – amber necklaces are highly colonized with commensal bacterial with a median of 4 bacteria/necklace (range 1-9) mainly coagulase-negative Staphylococci. These bacteria could become pathogenic in the right conditions.

It is important for health care providers to try to work with parents to understand the cultural, religious, or other significance of necklaces, bracelets, strings, or other bodily adornments that often encircle the neck, extremity or body of children. For some, the item was given by a family member or friend and the parents want to honor that person by having the young child wear the item. For others, it is a customary practice which parents follow and may or may not be aware of the reasons for the practice. For many families discussing with them the reasons for the practice and what is important about the practice and needs to be maintained, usually helps to clarify expectations. For example, for some Hispanic families, gold necklaces and bracelets are believed to ensure general safety of the child, and for many of these families the item does not have to encircle the body but just needs to be touching the skin to maintain its believed effectiveness. Some of these families will remove the item or be willing to move it to another location on the body or pin it inside the clothing to decrease the risks but still maintain skin contact with the item.

For a review of risks in everyday life click here.

Questions for Further Discussion
1. What other cultural or religious practices do you see in your practice that have potential health or safety risks?
2. How do you advise families about these risks?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Child Safety and Child Dental Health.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Taillefer A, Casasoprana A, Cascarigny F, Claudet I. Infants wearing teething necklaces. Arch Pediatr. 2012 Oct;19(10):1058-64.

Jacobson R. Amber Teething Necklaces Pose Choking Hazard. New York Times. October 11, 2013. Available from the Internet at http://well.blogs.nytimes.com/2013/10/11/amber-teething-necklaces-pose-choking-hazard/?_r=0 (cited 12/20/16).

Snyder S. Amber Waves of Woo. Science-Based Medicine. April 11, 2014. Available from the Internet at https://sciencebasedmedicine.org/amber-waves-of-woo/ (cited 12/20/16).

Mills E, O’Neill LA. Succinate: a metabolic signal in inflammation. Trends Cell Biol. 2014 May;24(5):313-20.

Tretter L, Patocs A, Chinopoulos C. Succinate, an intermediate in metabolism, signal transduction, ROS, hypoxia, and tumorigenesis. Biochim Biophys Acta. 2016 Aug;1857(8):1086-101.

Machet P, Lanotte P, Giraudeau B, Leperlier M, Tavernier E, Maruani A. Amber necklaces: reasons for use and awareness of risk associated with bacterial colonisation. Eur J Dermatol. 2016 Nov 21. [Epub ahead of print]

Cox C, Petrie N, Hurley KF. Infant Strangulation from an Amber Teething Necklace. CJEM. 2016 Aug 9:1-4. [Epub ahead of print]

Australian Academy of Paediatric Dentistry. Teething. Available from the Internet at http://aapd.org.au/articles/teething (cited 12/20/16).

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

What Causes Hyperammonemia?

Patient Presentation
An 11-year-old male had a recent viral illness. He was improving but during the night he got up to use the restroom, collapsed and died. He was later diagnosed with Reye’s syndrome. His parents, along with other parents and researchers, worked trying to find a cause and advocated for changes in medical practice. Aspirin in the setting of viral illnesses was determined to be a major risk factor, and with continued advocacy, aspirin and aspirin products had warning labels placed on them in 1986. This happy, young boy is still remembered through educational scholarships for local high school students dedicated to his memory.

Reye’s syndrome (RS)is named for Dr. Douglas Reye who along with Drs. G. Morgan and J. Baral described encephalopathy and fatty accumulation and degeneration in children in a 1963 Lancet article. RS usually affects children but can occur at all ages. All organs can be affected but the liver and brain are primarily affected causing liver failure and encephalopathy as toxic metabolites (especially ammonia) accumulate, and intracranial hypertension and cerebral edema occurs. As the ammonia levels begin to rise (> 100 mg/dL) patients lose their appetite, have nausea and emesis and mental status changes which includes personality changes, agitation/combativeness, disorientation and insomnia. As the levels continue to rise (150-200 mg/dL) loss of consciousness and seizures can occur. At levels of 200-400 mg/dL coma and respiratory failure can occur.

RS occurs after a previous viral illness, especially varicella or influenza, usually during the recovery phase. Research in the 1970s and 80s determined that salicylates (aspirin) were a major risk factor for RS although the mechanism is still not understood. Warning labels were added to salicylate products in the US starting in 1986. Aspirin is therefore not recommended for use for most acute childhood illnesses and has been replaced by acetaminophen or ibuprofen. Similar products such as bismuth subsalicylate products also should be used with great care at any time particularly around the time of a viral illness. This change in medical practice has caused the number of RS cases to dramatically decrease.

The differential diagnosis of RS includes viral and bacterial meningoencephalitis, sepsis, diabetes, poisons or drug overdose, liver failure, non-accidental trauma, sudden infant death syndrome or psychiatric problems.

Learning Point
The differential diagnosis of hyperammonemia includes:

  • Increased production
    • Protein load
      • Gastrointestinal hemorrhage or bypass
      • Parenteral nutrition
      • Multiple myeloma
      • Stem cell transplant, allogenic
    • Increased catabolism
      • Corticosteroids
      • Exercise, strenuous
      • Starvation
      • Seizures
    • Genitourinary problems
      • Congenital ureteric obstruction with associated infection
      • Urease-producing organisms (e.g. Proteus, Klebsiella) causing infection
    • Infectious
      • Herpes simplex virus infection
      • Severe systemic neonatal illness
      • Neonatal sepsis
      • Reye syndrome
  • Decreased elimination
    • Liver and biliary tract problems
      • Liver failure, acute or chronic
      • Biliary atresia
      • Porto-systemic shunt (vascular bypass) of the liver
    • Inborn errors of metabolism
      • Urea cycle enzyme defects
        • Ornithine transcarbamoylase (OTC) deficiency
        • Arginase deficiency
        • Argininosuccinate synthase (ASS) deficiency – citrullinemia
        • Argininosuccinate lyase (ASL) deficiency – argininosuccinic aciduria
        • Carbamoylphosphate synthase 1 (CPS 1) deficiency
        • N-Acetylglutamate synthase (NAGS) deficiency
      • Transport defects of urea cycle intermediates
        • Aspartate-glutamate shuttle (citrin) deficiency
        • Lysinuric protein intolerance
        • Mitochondrial ornithine transporter (HHH syndrome)
        • Methylmalonic acidemia
        • Organic acidemias
        • Propionic acidemia
      • Fatty acid oxidation disorders
        • Medium-chain acyl-CoA dehydrogenase deficiency
        • Long-chain fatty acid oxidation defects
        • Systemic primary carnitine deficiency
      • Galactosemia
      • Hyperinsulinism-hyperammonemia syndrome
      • Ornithine aminotransferase deficiency
      • Mitochondrial respirator chain defects
      • Pyruvate carboxylase deficiency
      • Tyrosinemia type 1
    • Medications
      • 5-pentanoic acid
      • Acetaminophen
      • Asparaginase
      • Aspirin
      • Carbamazepine
      • Cyclophosphamide
      • Rifampicin
      • Valproic acid
  • Miscellaneous
    • Transient hyperammonemia of the newborn
    • Sampling error – inappropriate sample or sample not analyzed immediately

    Questions for Further Discussion
    1. How to various inborn errors of metabolism present? For a discussion of inborn error of metabolism presentations click here.
    2. How does liver failure present?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Reye Syndrome

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    To view videos related to this topic check YouTube Videos.

    Reye RD, Morgan G, Baral J (1963). “Encephalopathy and fatty degeneration of the viscera. A Disease entity in childhood”. Lancet. 2 (7311): 749-52.

    Greeley Daily Tribune. Parents Fighting the Puzzle of Reye’s Syndrome. May 26, 1977, Thu, Page 53. Available from the Internet at https://www.newspapers.com/clip/117982/parents_fighting_the_puzzle_of_reyes/(cited 12/16/16).

    New York Times. Aspirin Labels to Warn About Reye Syndrome. March 8, 1986. Available from the Internet at http://www.nytimes.com/1986/03/08/us/aspirin-labels-to-warn-about-reye-syndrome.html (cited 12/16/16).

    National Institute of Neurological Diseases and Stroke. NINDS Reye’s Syndrome Information Page. Available from the Internet at http://www.ninds.nih.gov/disorders/reyes_syndrome/reyes_syndrome.htm (rev. 9/25/2009, cited 12/16/16).

    Singh P, Goraya JS, Gupta K, Saggar K, Ahluwalia A. Magnetic resonance imaging findings in Reye syndrome: case report and review of the literature. J Child Neurol. 2011 Aug;26(8):1009-14.

    Paprocka J, Jamroz E. Hyperammonemia in children: on the crossroad of different disorders. Neurologist. 2012 Sep;18(5):261-5.

    Ahrens-Nicklas RC, Edmondson AC, Ficicioglu C. An 8-year-old girl with abdominal pain and mental status changes. Pediatr Emerg Care. 2015 Jun;31(6):459-62.

    El-Hattab AW. Inborn errors of metabolism. Clin Perinatol. 2015 Jun;42(2):413-39, x.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • At What Radon Level Should Mitigation Be Considered?

    Patient Presentation
    A 2-year-old female came to clinic for her health supervision visit. The family had just moved into an old home. During the interview the mother noted that they had had the home checked for lead and for radon. “The radon test said it was normal,” she said. The pertinent physical exam was normal and the diagnosis of a healthy female was made. When discussing the toddler with the resident, the attending said that he didn’t know what was the normal value range for radon. “We don’t do regular screening for radon like we do for lead, so I just don’t know what normal is,” he stated. Later the attending found the numbers and also found more specific information about radon mitigation in his area to have for future encounters.

    Radon is a naturally occurring, radioactive gas that is colorless, odorless and tasteless. It is produced from the normal radioactive decay of uranium into radium and then into 222R-Radon. Radon gas escapes from soils and rocks into the air and generally concentrates in enclosed spaces such as buildings, mines and caves. The general ionizing radiation dose received by the general public is caused by radon in large part. In homes and other buildings, soil gas is the most important source of residential radon, but other sources which are less important includes building materials and well water sources.

    Indoor radon is the second leading cause of lung cancer after smoking in the US and a major cause of lung cancer deaths worldwide (3-14%). While children could be at higher risk for cancer because of radon exposure, there currently is not conclusive data that supports this. There also is no current strong evidence that radon causes cancers other than lung cancer.

    Radon testing is easy and inexpensive to perform. Depending on the building size, location, construction, materials and radon results, more than 1 testing may be needed to determine the overall risk. Repeated radon testing can also be considered if there is increased exposure such as living in a basement apartment. If more than 5% of current buildings in an have elevated radon, new housing and building construction should have preventive radon measures included as they are considered cost effective. Radon mitigation systems can be built into the new construction. For existing dwellings with elevated radion, specific mitigation techniques vary depending on the building construction and materials. Soil suction techniques gather radon from below or at the foundation and vent it away from the structure. There are numerous ventilation techniques that actively or passively increase the ventilation in particular areas or throughout the building to decrease, and hopefully eliminate, the radon concentration. Sealing cracks in foundations/walls is not considered an adequate mitigation technique by itself but can be used as one part of an overall mitigation plan.

    Learning Point
    Radon concentrates in locations close to the soil and in places with less ventilation. One study of primary schools in Serbia illustrates these points. Radon levels were higher in schools with only one floor, smaller buildings and located geographically in locations known to have higher naturally occurring radon levels. The higher up in the building there was a decrease in the radon levels. The authors point out that an “average” exposure for students really is not possible, as many other factors contribute to the risk including how the school rooms are used, and when are they used (e.g. higher levels on weekends and holidays when building is shut up more, or cold vs. warm seasons)

    The United States Environment Protection Agency provides a map of the general radon risk by county. The average level of radon in a US home is 1.3 pCi/L (picoCuries per liter), and about 0.4 pCi/L of radon is normally found in the outside air. Radon mitigation should be considered if the long term levels are 4.0 pCi/L or more. It would be best if there was no radon risk but that is not generally achieveable considering radon’s ubiquitous nature within the world.

    Questions for Further Discussion
    1. What is the risk of radon in your local area?
    2. What other environmental risks are in your local area?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for these topics: Radon and Indoor Air Pollution.

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    To view videos related to this topic check YouTube Videos.

    United States Environmental Protection Agency. Radon. Available from the Internet at https://www.epa.gov/radon (cited 12/13/16).

    United States Environmental Protection Agency. Consumers Guide to Radon Reduction. Available from the Internet at https://www.epa.gov/sites/production/files/2016-02/documents/2013_consumers_guide_to_radon_reduction.pdf (rev. 2013, cited 12/13/16).

    World Health Organization. WHO Handbook on Indoor Radon. Available from the Internet at http://www.who.int/ionizing_radiation/env/9789241547673/en/ (cited 12/13/16).

    World Health Organization. Radon. Available from the Internet at http://www.who.int/ionizing_radiation/env/radon/en/ (rev. 2009, cited 12/13/16).

    Bochicchio F, ZuniC ZS, Carpentieri C, et.al. Radon in indoor air of primary schools: a systematic survey to evaluate factors affecting radon concentration levels and their variability. Indoor Air. 2014 Jun;24(3):315-26.

    Del Risco Kollerud R, Blaasaas KG, Claussen B. Risk of leukaemia or cancer in the central nervous system among children living in an area with high indoor radon concentrations: results from a cohort study in Norway. Br J Cancer. 2014 Sep 23;111(7):1413-20.

    Peckham EC, Scheurer ME, Danysh HE, Lubega J, Langlois PH, Lupo PJ. Residential Radon Exposure and Incidence of Childhood Lymphoma in Texas, 1995-2011. Int J Environ Res Public Health. 2015 Sep 25;12(10):12110-26.

    Madureira J, Paciencia I, Rufo J, Moreira A, de Oliveira Fernandes E, Pereira A. Radon in indoor air of primary schools: determinant factors, their variability and effective dose. Environ Geochem Health. 2016 Apr;38(2):523-33.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital