Are products containing nanoparticles a health risk?

Since humans are routinely exposed to a number of materials containing nanoparticles, concerns exist about how such exposure affects human health.

Little is currently known about the long-term effects of exposure to engineered nanoparticles, but cell culture and animal studies have begun to offer clues. Complicating the effort to characterize effects is the number of different nanoparticles and applications, each of which may affect cells.

Data on the cellular effects of nanoparticles come mostly from in vitro cell culture nanotoxicology studies. However, no known studies to date have examined the effects of real-world exposures in humans, i.e., exposure levels that an average human being would experience in day-to-day life. Cell culture and animal studies have used exposure levels that are thought to be far greater than those experienced by an average person. From current research findings, no evidence exists of adverse changes in human health as a result of the use of nanoparticles currently on the market. However, the known adverse health effects of ultrafine particulate matter (dust and pollutants), which is also nanoscale-sized, suggests that the effect of engineered nanoparticles on human health warrants rigorous scientific study.

What is nanotechnology?

Nanotechnology is the understanding and control of matter at dimensions of approximately 1-100 nanometers.  For comparison, a sheet of pater is about 100,000 naonmeters thick and a human hair is about 80,000 nanometers thick and a DNA double helix is about 2.5 naonmeters in diameter.

The science of nanotechnology manipulates matter to create new and unique materials and products. Nanoparticle components are present in materials such as polymers, electronics, paints, batteries, sensors, fuel cells, solar cells, coatings, computers and display systems. Nanoparticles are also found in other consumer products such as, cosmetics and pharmaceuticals.

Commercial Application of Nanotechnology

Over 800 commercial products and applications of nanoparticle-based materials exist. Selected examples are:

  • nanoscale polymer composites that make baseball bats, tennis rackets, motorcycle helmets, automobile bumpers, luggage, and power tool housings more lightweight, stiff, durable, and resilient;
  • surface treatments of fabrics that help to resist wrinkling, staining, and bacterial growth and provide lightweight ballistic energy deflection in personal body armor;
  • nanoscale materials in cosmetic products that provide better coverage and absorption, increase antioxidant and antimicrobial properties, and filter UV light;
  • nanomaterials in computing, communications, and other electronics applications provide faster, smaller, and more portable systems that can manage and store larger amounts of information; and,
  • nanocomposites in food containers minimize carbon dioxide leakage out of carbonated beverages, or reduce oxygen inflow, moisture outflow, or the growth of bacteria to keep food fresh and safe for longer periods of time.

Medical Applications of Nanotechnology

Nanotechnology is being widely applied in many facets of health care. For example, quantum dots (semi-conducting nanocrystals) show unique optical and electronic properties like size-tunable light emission, simultaneous excitation of multiple fluorescence colors, high signal brightness, and long-term photostability. These properties have enhanced both in vitro and in vivo biological imaging, and are being used to image sentinel lymph nodes, tumor-specific receptors, malignant tumor detectors, and tumor immune responses.

In another example, nanoparticle-based hydrogels used as wound dressings have been introduced. Nanoscale inorganic particles have been added to hydrogels as reinforcing agents, improving the strength, elasticity, absorptive capability, and barrier properties of the wound dressing.

Oversight and Regulation of Nanotechnology Products

Existing statutes and responsibility to protect the health of the public provide a foundation for the FDA’s regulation and oversight of nanomaterials. The FDA has not adopted a regulatory definition of “nanomaterial;” instead, it has taken a broadly inclusive approach to considering whether products contain nanomaterials or involve nanotechnology.

In Summary:

Nanotechnology has demonstrated great benefit in the improvement of consumer products and applications. Little is known about how nanomaterials affect human health and the environment, but preliminary research has shown that acute exposure to nanoparticles can affect cellular behavior and may be toxic to some components of the environment. More detailed research is needed to examine how real-world exposure levels affect human health and the environment. In the meantime, regulation of products or applications that include nanomaterials will occur on a case-by-case basis, using science-based methods to evaluate the balance of benefits and risks. AMA policy is strongly supportive of the FDA’s mission to protect the health of the public, and of the EPA’s efforts to ensure that the public is protected from environmental pollution.

Read the full AMA Council on Science and Public Health Report on Nanotechnology and Safety Regulation.

Russell W. H. Kridel, M.D.

Is it safe to go through the full body x-ray scanners at airports?

Several years ago, the Transportation Security Administration (TSA) began installing and using advanced imaging technology (AIT) at airport passenger screening checkpoints as a secondary measure to detect security threats. By early 2010, AIT was widely implemented as a primary measure because AIT is more effective at detecting weapons, explosives, and other hazardous and/or concealed items hidden under clothing than older metal detector-based screening units. The two main types of AIT used are “backscatter” models, which use low levels of ionizing radiation, and “millimeter wave” models, which use radio waves.

Debate centers on exposure to ionizing radiation from backscatter screening. Although, backscatter units use extremely low levels of ionizing radiation, concern exists that any increase exposure to radiation is biologically dangerous. Although few data exist about the safety of millimeter wave scanners, they are not believed to have carcinogenic potential, so the focus of this discussion is on backscatter screening.

Backscatter Scanner

Ionizing radiation refers to radiation that has sufficient energy to ionize atoms or molecules (cause separation of electrons from an atom) in biological systems. The electrons and positively-charged ions released as a result of ionization can cause cellular damage. X-rays, gamma rays, beta particles (high-speed electrons), neutrons (heavy uncharged particles), and alpha particles (heavy charged particles) are the principal types of ionizing radiation encountered. Of these types, x-ray and gamma rays have the lowest rate of energy transfer.

Backscatter scanning units direct an x-ray beam over the surface of the body; the x-rays are low intensity, and therefore do not travel deep into tissues or through the body as those of a medical x- ray would. Instead, the majority of the rays are reflected back from the skin. Detectors translate the reflection pattern into an image that is examined by security personnel. The backscatter pattern is dependent on material property, and thus distinguishes between organic and inorganic materials.

The imperatives raised in these resolutions are diminished somewhat based on the U.S Transportation Security Administration’s (TSA) decision in early 2013, to remove the backscatter models from U.S. airports by June 2013 and replace them with millimeter wave models. This followed an October 2012 announcement that the TSA had removed backscatter scanners from the majority of large airports, placing them in smaller airports.  According to news reports, the backscatter models removed from airports in 2013 will likely be placed in federal buildings and other locations in which security measures are needed instead. However, depending on the frequency of exposure for employees and visitors of locations in which the backscatter units may eventually be placed, the concerns raised in the Council resolutions continue to warrant examination.

In conclusion, no studies have demonstrated negative health effects in passengers scanned by backscatter units, and the cancer risk from exposure appears to be miniscule. The Council on Science and Public Health believes that no data currently exist to suggest

Current Millimeter Wave Scanner

that passengers should avoid being screened by backscatter scanners. However, it supports continued research on the safe use of the scanners, as well as maintenance, calibration, survey, and officer training procedures that are meant to ensure that the units operate as intended. The Council notes that passengers who do not wish to undergo backscatter screening may opt for alternative screening. The Council also notes that no adverse health consequences are known to occur from millimeter wave models that have replaced the backscatter models.

Read the full AMA Council on Science and Public Health Report on “Safety of X-Ray Security Scanners”.

Russell W.H. Kridel, M.D.




There are a lot of drug shortages. Is there anything being done to reduce or prevent them?

National drug shortages continue to threaten patient care and safety. The existence of a shortage may compromise and delay treatment leading to progression of disease, adverse outcome, or therapeutic failure.

Sources of Information on Drug Shortages: Data on drug shortages comes from different points across the supply chain.  There are two major resources:

  1. The Food and Drug Administration (FDA). The FDA tracks and focuses on shortages of “medically necessary “ drugs.
  2. The American Society of Health-System Pharmacists (ASHP) Drug Shortage Resource Center tracks all drug shortages.

In addition, wholesalers may voluntarily submit information on supply interruption, as well as hospitals, individual practitioners or the public.

General Causes of Drug Shortages: Shortages have worsened appreciably over the last few years. Compared with 2005, twice as many drug shortages were identified in 2008, and in 2010 almost 180 shortages of medically necessary drugs were identified by the FDA — triple the amount from 2005.

Sterile injectables comprise the most common type of shortage, with 72% of the shortages in 2012 involving such preparations.

The most prominent causes include manufacturing difficulties and regulatory compliance issues; corporate decision leading to product discontinuation; consolidation of the pharmaceutical industry; and raw, bulk, or active pharmaceutical ingredient shortage. Only 5 companies manufacture 85% of injectable generics.

Action Being Taken to Reduce Shortages: Early notification from manufacturers of any issue that could lead to a potential disruption in product supply has been, and will continue to be, critical to preventing or mitigating drug shortages.

On July 9, 2012, President Obama signed into law the Food and Drug Administration Safety and Innovation Act (FDASIA) of 2012.  In the new law, Congress provided FDA with new authorities to help combat shortages of drug products in the United States and imposed new requirements on manufacturers regarding early notification to FDA of issues that could lead to a potential shortage or disruption in supply of a product.

The enhanced authorities include the following:

  • The scope of the early notification requirement has been broadened by requiring all manufacturers of covered drugs to notify FDA of potential discontinuances.  The prior law applied only to sole manufacturers.
  • Manufacturers are required to report discontinuances to FDA regardless of whether they intend to discontinue the product permanently or are facing only a temporary interruption of supply.
  • FDASIA enabled FDA to require, by regulation, mandatory reporting of shortages of biological products.  The prior law excluded all biological products from the reporting requirements.
  • Clarification was made that the notification requirement applies to drugs that are used in emergency medical care or during surgery (if they are intended for use in the prevention of a debilitating disease or condition).
  • Requirement made for FDA to issue a non-compliance letter to manufacturers who fail to comply with the drug shortage notification requirements and to make the letter and the company’s response to the letter available to the public.

In addition to these new authorities, FDASIA included other provisions related to drug shortages which are outlined on their website.

The Food and Drug Administration Safety and Innovation Act also required a GAO report examining the causes of drug shortages and formulating recommendations to prevent or alleviate shortages. The next GAO report should be coming out in December 2013 or January 2014.

Clinical Impact of Drug Shortages: Nearly 90% of the hospitals reported a drug shortage in the second half of 2010 that either caused a patient safety issue, resulted in the delay or cancellation of a procedure, required more expensive substitutes, or resulted in a pharmacist having to compound a drug formulation.

More than 80% of the time, shortages occurred without advanced warning.  And two-thirds of physicians surveyed said patient outcomes were adversely affected.

Summary: National drug shortages continue to threaten patient care and safety. The AMA Council on Science and Public Health recognizes the importance of drug shortages and will continue to evaluate the issue and report on updates and progress being made for improvement or resolution.

Read the 2011 AMA Council on Science and Public Health Report on Drug Shortages and the 2012 Council Update on Drug Shortages.

Russell W.H. Kridel, M.D.

What are some easy steps I can do to lose weight and reduce sugar in my diet?

Here are 6 simple and easy steps you can take right now to lose weight and get started on a healthier lifestyle.

  1. Drink 1 less sugar based drink a day — with the goal of no longer having it as part of your daily diet.
  2. Downsize your drink.  Ask for a small instead of a large.  For example, a super-size soda contains the equivalent of 4 or 5 regular 12 ounce cans, which contains about 48 packets of sugar and has 720 calories.
  3. Replace one sugary drink with water every week. Substituting water for one 20 ounce sugar-sweetened soda will save you about 240 calories.
  4. Switch from fruit juice to real fruit.  Fruit juice has added sugar.
  5. Stop drinking energy or sports drinks.  Water is all you need to stay hydrated, even when you exercise.
  6. If you are a parent, don’t buy sugar-sweetened drinks.  It is a lot easier to avoid drinking sodas and sugary drinks if they are not in the cabinets at home.

Reducing intake of sugar-sweetened beverages is one of the simplest ways to reduce intake of added sweeteners.  And, given the strong association of sugar-sweetened drinks with body weight and obesity, it is also a very simple way to reduce calorie intake and therefore lose weight.

Certainly, it is most optimal to cut out sugar-sweetened drinks entirely.  However, just by eliminating one sugared sweetened beverage (SSB) a day, you will be well on your way to better health.

Read the AMA Council on Science and Public Health Report on sugar-sweetened drinks.

Russell Kridel, MD

What are e-cigarettes?

Electronic cigarettes, known as E-cigarettes, are non-flammable devices that deliver synthetic or tobacco-derived nicotine; they are similar in size, shape, and usage to their leaf tobacco counterparts. They are available worldwide through the Internet or increasingly in retail outlets.

However, due to the lack of rigorous chemical and animal studies, as well as clinical trials on commercially available e-cigarettes, neither their value as therapeutic aids for smoking cessation nor their  “safety” as cigarette replacements is established and remains speculative.

E-cigarettes consist of three integrated parts contained in a stainless steel shell: the mouthpiece (or nicotine cartridge), the atomizer chamber (or  vaporizer), and a smart chip lithium ion battery.  Typically, a disposable filter holds a cartridge containing synthetic nicotine dissolved in propylene glycol, water, and flavorings.

When the entire unit is assembled, the user creates an inhaling motion which activates the battery via pressure sensors. The battery powers the vaporizer, and the vaporizer heats the liquid housed in the mouthpiece. As such, the electronic cigarette is a delivery device for the addictive substance nicotine. The vapor released is polyethylene glycol (PG), which looks like cigarette smoke (also used for theatrical smoke) and is also an FDA-approved food additive. The volume released varies by brand, but when inhaled feels like cigarette smoke to users. Unlike tobacco smoke, the vapor quickly evaporates, leaves no remaining odor, but the secondhand smoke may still be irritating.  Compared with conventional cigarettes, which last for about fifteen puffs, e-cigarettes can sustain 150 to 300 puffs, the equivalent of one-half to one pack of cigarettes. The cartridges vary in nicotine strength, being characterized as “zero,” low, medium, or high. Disposable, non-refillable versions, equivalent to one or two packs of cigarettes, also are available.

In tests conducted by the FDA’s Division of Pharmaceutical Analysis on two brands of e-cigarettes, additional ingredients were detected including diethylene glycol in one cartridge (a component of antifreeze and toxic to humans) and tobacco-specific nitrosamines (a known carcinogen) in half of the samples. This is very concerning and adds to the premise that such items should be closely regulated.

E-cigarettes were invented by an employee (Hon Lik) of a Chinese electronics company (Ruyan) headquartered in Beijing, which began marketing e-cigarettes in 2004. The Ruyan Group remains the leading manufacturer of e-cigarettes (sold as Ruyan® e-cigarettes), but additional manufacturers using similar devices have subsequently entered the market, offering their products worldwide via the Internet, in shopping malls, and other distributors. Prices for the devices (a charger, rechargeable battery, and five nicotine cartridges) range from about $80 to $150 with packages of replaceable cartridges, each good for several uses, costing $10 to $15 or the equivalent of 1 to 1.5 packs of cigarettes.

Per the CSAPH report, manufacturers of e-cigarettes have not submitted the requisite applications for FDA approval of these products for smoking cessation. And the Food and Drug Administration (FDA) has warned the public against e-cigarettes, saying they cannot be considered legitimate therapy for smokers to quit and that they could turn children into smokers.

Questions answered by Russell W.H. Kridel, M.D. as a public service to patients concerned about current health issues. All of the facts are gathered from published reports of AMA Council on Science and Public Health and approved by the AMA House of Delegates.

Read the AMA Council on Science and Public Health Report on “Use of Electronic Cigarettes in Smoking Cessation.”

Russell W.H. Kridel, M.D.

Does bottled water have fluoride in it?

Most bottled water is low in fluoride and lacks sufficient fluoride levels to prevent tooth decay.

However, most municipal drinking water sources do include fluoridation to reduce dental caries.

Drink tap water.  Your dentist and your bank account will be happier.

Read the AMA Council on Science and Public Health Report on “Safety of Bottled Water”.

Russell W.H. Kridel, M.D.

Why is salt the new target in the media?

You may have seen or read about a subway ad campaign that kicked off this week in NYC by the city’s Department of Health that urged consumers to reduce salt consumption.

NYC Subway Campaign

The concern over public salt consumption and salt levels in common food products is not really new news. In a 2006 Report on the Promotion of Healthy Lifestyles, the AMA Council on Science and Public Health addressed the issue of reducing the population burden of cardiovascular disease by reducing sodium intake. You can read a summary of the report here.

The CSAPH stated the public health advice to reduce sodium intake, such as that recently in NYC, is intended to influence the overall distribution of sodium intakes and, thereby, the incidence of hypertension in the population. With an appropriate food industry response, combined with consumer education and knowledgeable use of food labels, the average consumer should be able to choose a lower sodium diet without an inordinate level of dietary restriction, inconvenience, or loss of food enjoyment.

If we could change what the food companies and restaurants do, we can change the consumer’s mindset. And the result will be less cardiovascular disease and improved health overall for our population.

Russell Kridel, MD


Are flu vaccinations just for high-risk groups, like the elderly?

No. Flu vaccinations are not just for high-risk groups. The current policy states that routine annual influenza vaccinations are recommended for all adolescents and adults age 6 months and older.

Optimally, vaccination should occur before the onset of influenza in the community. Therefore, vaccinations are offered as soon as a vaccine is available to the public.  In addition, vaccinations are made available throughout the flu season as long influenza viruses are circulating in your community.

Previously, it was recommended that persons at high risk for complications from influenza should be the priority.  But, that is no longer the case.

Read the AMA Council on Science and Public Health Report on Influenza and Influenza Vaccine.

Russell Kridel, MD

Why is there so much concern about sugar-sweetened beverages?

Consumption of sugar-sweetened beverages has been strongly and consistently associated with obesity and a number of related cardiometabolic conditions such as type 2 diabetes and coronary heart disease. A child’s risk of becoming obese increases by 60% for every additional sugary drink consumed per day.  And, women who drink one sugar-sweetened beverage each day have almost twice the risk of diabetes.

Americans consume 200 to 300 more calories each than we did 30 years ago.  And, nearly half of these extra calories come from sugar-sweetened drinks, often displacing other foods and drinks rich in nutrients from a diet, such as skim milk and whole fruit. For example, a 20-oz serving of a sugar-sweetened  soda contains the equivalent of 16 packets of sugar.

Limiting consumption of sugar-sweetened beverages will improve your health.  An average person would lose about 9 pounds a year by eliminating sugar-sweetend beverages from their diet.  For example, substituting water for one 20-ounce soda will save you about 240 calories.

Read the AMA Council on Science and Public Health Report on sugar-sweetened drinks.

Russell Kridel, MD

As a 40+ female, should I get a mammogram? There seems to be different points of view in the media.

Mammography is a proven method for detecting breast tumors, with demonstrated reductions in mortality for women who undergo regular screening.

Every woman age 40 years and older who wants a routine screening mammogram and whose physician believes it is clinically appropriate should receive one, regardless of her insurance coverage status.

Read the report from the AMA Council on Science and Public Health about the importance of women over 40 having a mammogram.

Russell Kridel, MD