Dr. Jake’s Notes

Why MRI?

A recent study of Washington State WC data confirms the absence of benefit, and potential adverse consequences, of having early Magnetic Resonance Imaging or MRI after injury.

1226 workers with acute low back injuries were analyzed, of which 78% had “sprains” and 22% were diagnosed with radiculopathy (irritation of spinal nerve roots).

In both segments, early MRIs (within 6 weeks of injury) correlated with a higher likelihood of work disability at one year. Early MRI recipients fared no better than other workers. And those diagnosed with radiculopathy did no better than those with sprains, meaning that these diagnostic categories do not necessarily predict outcomes.

The message is that an early MRI in the course of a low back injury may not be useful or necessary.

Of course, there are specific red-flag indicators that suggest an emergent MRI is critical, but these are rare occurrences.

Thinking about aluminum

An Italian study recently tested the effects of aluminum on naval welders. An ongoing controversy about the metal’s effect on the neurocognitive system persists despite many studies.

Shipyard workers, compared to a control group, demonstrated deficits in cognitive function, particularly related to attention and memory performance. These alterations in function were directly proportional to the duration of exposure and the quantity of aluminum absorbed.

Speaking up against noise pollution

A recent audiology study in New Zealand concluded that occupational noise is a significant contributor to disabling hearing loss worldwide. Noise-induced hearing loss (NIHL) has resulted in huge human and economic consequences.

While hearing protection devices (HPDs) are available, inconsistent and improper use of these devices has hindered efforts to prevent NIHL.

The authors believe that further research to identify personal and environmental factors is necessary, followed by renewed interventions to promote HPD amongst workers.

Climb every mountain (but take 600 mg of ibuprofen)…

Workers at high altitudes, as well as recreational climbers, should take note of a recent randomized controlled trial in California’s White Mountains, addressing the prevention of mountain (altitude) sickness.

The trial studied hikers climbed from 4000 to more than 12,000 feet levels over 12 hours. Compared to hikers receiving a placebo, those who received ibuprofen (e.g. Motrin) throughout the day, had a significantly lower risk of developing mountain sickness, and also had less severe symptoms if they did develop it.

The safety profile of ibuprofen makes it more attractive than various prescription drugs used for the same purpose.

At least it doesn’t cause cirrhosis…

It had been believed that occupational exposure to vinyl chloride was associated with cirrhosis, a liver condition leading to liver failure and death.

A recent Italian meta-analysis does not support this relationship. (A meta-analysis is an aggregation of data from multiple separate studies, which permits conclusions to be drawn from a larger population, with greater statistical validity).

The analysis demonstrated that: “Overall, our findings indicate the absence of increased risk of death from cirrhosis in vinyl chloride-exposed workers.” However, this chemical is a known carcinogen (cancer-causing agent) and should be carefully monitored.

Vinyl chloride is used to manufacture plastic products, including polyvinyl chloride (“PVC”) plastics.

Particulately interesting…

Occupational exposure to inhaled particles predisposes workers to strokes, according to a Swedish study, spanning 18 years of data.

Job exposure to environmental particles increased the risk of both ischemic and hemorrhagic stroke. (Ischemic stroke is caused by disruption of blood supply to a brain region. Hemorrhagic stroke is due to leakage of blood from a vessel into brain tissue.)

The risk was higher for women than men, and for those with 5 or more years of exposure.

Working Data From The U.K…

A recent analysis compiled by the UK’s Health and Occupational Reporting network in General Practice (THOR-GP) offers a picture of work injury and absence derived from 2006-2009 data from Great Britain.

Some of the key observations:

• 53% of claims were musculoskeletal (MSK); 31% were mental ill-health.
• 56% of reported cases had work-absence.
• 81% of mental cases had absence, compared to 50% of MSK cases.
• Public sector employees had higher absence rates than private sector employees.
• Self-employed individuals had lower absence rates.

In the United States, a 1990 study by the National Institute for Occupational Safety and Health (NIOSH) found similar findings here. The study showed 48.7% of claims were muscolskeletal and represent ambulatory presentations similar to the UK study.

Spending too much is not the only risk…

The U.S. Department of Labor’s Occupational Safety and Health Administration is encouraging major retail employers to take precautions to prevent worker injuries during major sales events during the holiday season.

In 2008, a worker was trampled to death while a mob of shoppers rushed through the doors of a large store during a Black Friday sales event.The store was not using the kind of crowd management measures recommended in OSHA’s fact sheet, which is available online at http://www.osha.gov/OshDoc/data_General_Facts/Crowd_Control.html .

The fact sheet provides employers with recommended elements for crowd management plans. Plans should include having trained security personnel or police officers on-site. Barricades or rope lines should be set up for pedestrians well in advance of customers arriving at the store. These barricades should be set up so that the customers’ line does not start right at the entrance of the store. Emergency procedures address potential dangers. Having security personnel or customer service representatives explain entrance procedures to the arriving public can also help ensure safe shopping.

Erionite is the new asbestos…

Erionite is a naturally occurring mineral that belongs to a group of silicate minerals called zeolites. It is usually found in volcanic ash that has been altered by weathering and ground water. Like naturally occurring asbestos, deposits are present in many Western states. Disturbance of this material can generate airborne fibers with physical properties and health effects similar to asbestos.

Until recently, erionite was not generally considered to be a potential hazard in North America, in part because relatively little risk for exposure was seen. However, evidence has slowly accumulated linking exposure to erionite with serious adverse health effects in North America, and suggesting that some workers may have a greater potential for exposure than previously recognized.

There have been several documented cases, involving road construction workers and pit miners, in which lung disease (fibrosis) and mesothelioma was attributable to erionite deposits in lung tissue.

Risk reduction recommendations to limit erionite exposures of workers who engage in activities that disturb erionite-containing gravel/soil or crush rocks that contain erionite can include:

• Training workers about the potential hazards of erionite and control methods for reducing the potential for exposure
• Avoiding the use of erionite containing aggregate whenever possible
• Using wet methods to reduce dust generation for road and other work such as in quarries where erionite is present (e.g., when drilling rock, apply water through the drill stem to reduce airborne dust, or use a drill with a dust collection system)
• Establishing decontamination protocols including change of clothing, showering before leaving the worksite, and appropriate cleaning/disposal of personal protective equipment
• Ensuring work clothing is not washed at home to prevent erionite fibers from being brought home
• Protecting employees with personal protective equipment, including respiratory protection.

These recommendations appeared in a NIOSH blog recently (National Institute for Occupational Safety and Health).

As long as the surgeon is still sharp…

Surgeons and their assistants are especially at risk of exposure to blood due to glove perforations and needle stick injuries during operations.The use of blunt needles can reduce this risk because they don’t penetrate skin easily but still perform sufficiently in other tissues.

A Finnish analysis derived this conclusion based on 10 randomized clinical trials involving nearly three thousand surgeons.

Surgeons using sharp needles typically sustain one glove perforation per 3 operations. Blunt needles reduce the risk by about 50%. Additional force is needed to use blunt needles, but was still deemed acceptable by the majority of surgeons.

Chemical solvents and Parkinson’s Disease…

An NIH (National Institutes of Health) funded study compared sets of twins in which only one twin had Parkinson’s.

Both twins’ occupational histories were examined for exposure to six chemicals.Researchers concluded that two common chemical solvents, trichloroethylene(TCE) and perchloroethylene (PERC), are significantly linked to development of this disease. Job categories implicated in exposures included: industry machine repair, industrial workers, dry cleaning, degreasing.

The team evaluated 99 pairs of twins; twin studies are helpful for identifying the purely environmental influences in disease, since the genetic backgrounds are identical.

Not enough fires to fight…

A Harvard School of Public Health study revealed that 45% of on-duty fatalities in male firefighters are due to cardiovascular disease (CVD).

Apparently firefighters are not particularly fit. There is a high prevalence of obesity and sedentary behavior, and 28% of them meet criteria for metabolic syndrome (MetSyn), a condition which is a precursor for CVD events. MetSyn is a constellation of risk factors (abdominal obesity; abnormal lipid levels such as triglycerides and cholesterol; high blood pressure; abnormal blood sugar levels).

The authors conclude that firefighters should be incentivized to improve their fitness, in order to reduce the CVD burden in this population.