Electronic Cigarettes Contain Higher Levels of Toxic Metal.


Electronic Cigarettes Found To Contain Dangerous Metal Nanopartices

A concerning new study found that the aerosol from electronic cigarettes contains higher levels of measurable nanoparticle heavy metals than conventional tobacco smoke.

A new study published in the journal PLoS One has uncovered a concerning fact about electronic cigarettes (EC): toxic metal and silicate particles including nanoparticles are present in both the cigarette fluid and aerosol.1

Researchers at the Department of Cell Biology and Neuroscience, University of California Riverside, tested the hypothesis that electronic cigarettes (EC) contain metals from various components in EC.  They employed a variety of testing methods to ascertain the level of contamination, including light and electron microscopy, cytotoxicity testing, and x-ray microanalysis. Their results were reported as follows:

The filament, a nickel-chromium wire, was coupled to a thicker copper wire coated with silver. The silver coating was sometimes missing. Four tin solder joints attached the wires to each other and coupled the copper/silver wire to the air tube and mouthpiece. All cartomizers had evidence of use before packaging (burn spots on the fibers and electrophoretic movement of fluid in the fibers). Fibers in two cartomizers had green deposits that contained copper. Centrifugation of the fibers produced large pellets containing tin. Tin particles and tin whiskers were identified in cartridge fluid and outer fibers. Cartomizer fluid with tin particles was cytotoxic in assays using human pulmonary fibroblasts. The aerosol contained particles >1 µm comprised of tin, silver, iron, nickel, aluminum, and silicate and nanoparticles (<100 nm) of tin, chromium and nickel. The concentrations of nine of eleven elements in EC aerosol were higher than or equal to the corresponding concentrations in conventional cigarette smoke. Many of the elements identified in EC aerosol are known to cause respiratory distress and disease.

The study authors concluded that “The presence of metal and silicate particles in cartomizer [atomizer/cartridge connecting to the battery] aerosol demonstrates the need for improved quality control in EC design and manufacture and studies on how EC aerosol impacts the health of users and bystanders.”

Cartomizer Anatomy

Discussion

While e-cigarettes are rightly marketed as safer than conventional tobacco cigarettes, which contain thousands of known toxic compounds including highly carcinogenic radioactive isotopes, they have not been without controversy.  In May 2009, the US Food and Drug Administration Division of Pharmaceutical Analysis found diethylene glycol, a poisonous liquid used in explosives and antifreeze, in one of the cartridges they sampled. They also discovered the cancer-causing agent, tobacco-specific nitrosamines, in a number of commonly used brands.2

The findings of this latest PLoS One study refutes proponents of e-cigarettes who claim that the health risks of smoking are eliminated with their use. Heavy metals like tin, aluminum, cadmium, lead and selenite are increasingly being recognized as carrying significant endocrine disrupting potential and belong to a class of metals known as ‘metalloestrogens.’

One of the unintended, adverse consequences of nanotechnology in general is that by making a substance substantially smaller in size than would occur naturally, or though pre-nanotech production processes, the substance may exhibit significantly higher toxicity when in nanoparticle form. Contrary to older toxicological risk models, less is more: by reducing a particle’s size the technology has now made that substance capable of evading the body’s natural defenses more easily, i.e. passing through pores in the skin or mucous membranes, evading immune and detoxification mechanisms that evolved millions of years before the nanotech era.

For example, when nickel particles are reduced in size to the nanometer range (one billionth of a meter wide) they may actually become more toxic to the endocrine system as now they are capable of direct molecular interaction with estrogen receptors in the body, disrupting their normal structure and function.3 4 5 Moreover, breathing these particles into the lungs, along with other metals, ethylene glycol and nicotine produces a chemical concoction exhibiting synergistic toxicity, i.e. the toxicity of the whole is higher than the sum of their parts. These sorts of “chemical soups” are exceedingly difficult to study, as they embody a complexity that analytical and theoretical models within toxicology are not equipped to readily handle. Nonetheless, it is likely that when taken together the harms done by e-cigarettes are significant, and will likely manifest only after chronic use when identifying ‘singular causes’ of disease is nearly impossible. Regulators will have a hard time, therefore, identifying a “smoking” gun even after a broad range of health issues do emerge in exposed populations.

Ultimately, finding a less harmful alternative to tobacco smoking is justified, but let buyer (and user) beware, the products are not without possible harm as some marketers falsely advertise.

 

Pulmonary drug delivery: from generating aerosols to overcoming biological barriers—therapeutic possibilities and technological challenges.


Summary

Research in pulmonary drug delivery has focused mainly on new particle or device technologies to improve the aerosol generation and pulmonary deposition of inhaled drugs. Although substantial progress has been made in this respect, no significant advances have been made that would lead pulmonary drug delivery beyond the treatment of some respiratory diseases. One main reason for this stagnation is the still very scarce knowledge about the fate of inhaled drug or carrier particles after deposition in the lungs. Improvement of the aerosol component alone is no longer sufficient for therapeutic success of inhalation drugs; a paradigm shift is needed, with an increased focus on the pulmonary barriers to drug delivery. In this Review, we discuss some pathophysiological disorders that could benefit from better control of the processes after aerosol deposition, and pharmaceutical approaches to achieve improved absorption across the alveolar epithelium, prolonged pulmonary clearance, and targeted delivery to specific cells or tissues.

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Conclusions

Since the introduction of the first metered dose inhalers to the market in 1956,88 pulmonary drug delivery has made substantial progress, even leading to the first introduction of an inhalation form of insulin (Exubera) to the market. However, since the withdrawal of Exubera from the market in 2007, the field of advanced pulmonary drug delivery, other than delivery of anti-asthma and bronchodilating drugs, has stagnated. Until now the main focus of research and development efforts has been on generation of better aerosols by engineering more sophisticated particles or devices. However, optimised aerosol deposition is a necessary, but not sufficient component of pulmonary drug delivery. To overcome the biopharmaceutical challenges associated with absorption across the alveolar epithelium, control of particle clearance and targeting of specific regions or cells within the lungs requires a thorough understanding of the processes occurring at the cellular and non-cellular elements of the air—blood—barrier after aerosol drug deposition.

To achieve these goals, advanced in-vitro models, preferentially based on human cells and tissues, will be important. Furthermore, nanotechnology might contribute to the development of aerosol drug carriers, and might be necessary for the success of pulmonary drug delivery in the future.

Source: Lancet

 

 

 

 

Pulmonary drug delivery: from generating aerosols to overcoming biological barriers—therapeutic possibilities and technological challenges.


Research in pulmonary drug delivery has focused mainly on new particle or device technologies to improve the aerosol generation and pulmonary deposition of inhaled drugs. Although substantial progress has been made in this respect, no significant advances have been made that would lead pulmonary drug delivery beyond the treatment of some respiratory diseases. One main reason for this stagnation is the still very scarce knowledge about the fate of inhaled drug or carrier particles after deposition in the lungs. Improvement of the aerosol component alone is no longer sufficient for therapeutic success of inhalation drugs; a paradigm shift is needed, with an increased focus on the pulmonary barriers to drug delivery. In this Review, we discuss some pathophysiological disorders that could benefit from better control of the processes after aerosol deposition, and pharmaceutical approaches to achieve improved absorption across the alveolar epithelium, prolonged pulmonary clearance, and targeted delivery to specific cells or tissues.
Source: Lancet

Measuring Aerosol Production from Patients with Active TB.


Twenty-eight of 101 patients with culture-confirmed pulmonary tuberculosis had culture-positive cough aerosols, suggesting infectiousness; likelihood of a culture-positive aerosol was directly correlated with degree of sputum-smear positivity.

Although tuberculosis (TB) is transmitted by aerosols of droplet nuclei <5 µm in diameter, determination of infectiousness has been based on microscopic examination of sputum for the presence of organisms (smear assessment) — a method that may be neither sensitive nor specific. The magnitude and particle-size distributions of the aerosols generated by patients with active TB are unknown.

In a study conducted in Uganda, researchers attempted to collect, quantify, and size the aerosols produced by voluntary coughing in patients with active pulmonary TB and to compare these findings with results from sputum smears and aerosol cultures. Patients with culture-confirmed TB were asked to cough in two 5-minute sessions into a custom-built chamber that analyzed and collected their cough aerosol. Plates within the chamber contained 7H11 agar for mycobacterial culture.

Among the 101 patients, 28 produced aerosols that grew Mycobacterium tuberculosis. The proportion of patients who generated culture-positive aerosols increased significantly as the sputum smear microscopy grade increased (P=0.03). All patients with a culture-positive aerosol were smear positive; none of those with a negative smear produced a culture-positive aerosol. More than 96% of the culturable particles collected were between 0.7 and 4.7 µm in diameter.

Comment: Although the authors conclude that cough aerosols might provide a better determination of infectiousness than smear assessment, the data indicate that smear results correlate well with aerosol culture results.

Source: Journal Watch Infectious Diseases