Does Working the Night Shift Cause Cancer?

February 13, 2017

Many people experience interruptions in light-dark cycles due to the use of electronic devices at night, the location of their residences, or working at night (e.g., shift work). Exposures to artificial light at night or changes in the timing of exposures to natural light (such as with jet lag) may disrupt biological processes controlled by endogenous circadian rhythms, potentially resulting in adverse health outcomes. The National Institutes of Environmental Health Sciences (NIEHS) National Toxicology Program (NTP) is conducting health hazard assessments focusing on cancer (ORoC) and non-cancer health outcomes.

Light at night (LAN) has been nominated for review for possible listing in the Report on Carcinogens (RoC). One of the reasons cited for the nomination was the 2007 International Agency for Research on Cancer (IARC) Working Group conclusion that “shift work that involves circadian disruption” is probably carcinogenic to humans (Group 2A) (IARC 2010). IARC’s conclusion was based on limited evidence in humans for the carcinogenicity of shift work that involves night work (presumed to be a proxy for light at night) and sufficient evidence in experimental animals for the carcinogenicity of light during daily dark period (biological night)

NTP recently published a protocol to provide the methods and guidance that will be used to prepare the cancer hazard evaluation component of the draft Report on Carcinogens (RoC) monograph on Health consequences of electric lighting practices in the modern world. This monograph will evaluate whether scenarios associated with exposure to electrical light that lead to circadian disruption, including light at night, shift work at night, and trans-meridian travel, are associated with cancer risk.

One in Four Americans Have Noise Induced Hearing Loss

It’s hard to know when your hearing is damaged, unless you have a hearing test. About 1 out of 4 US adults who report excellent to good hearing already have hearing damage. A new CDC Vital Signs report finds that many of those with hearing damage report no workplace noise exposure.

About 40 million US adults aged 20–69 have hearing damage in one or both ears that may be due to noise exposure. CDC found that more half of those (53%) report no exposure to loud noise at work. Based on the information they provided, researchers believe their exposure to loud sounds comes from everyday activities in their homes and communities.

Noise exposure is the second most common cause of hearing loss (aging is first.) The louder a sound is and the more often a person is exposed to it, the more likely it will damage hearing. Common activities in homes and communities—such as using gas-powered lawnmowers or leaf blowers or attending a rock concert or ball game—can cause permanent hearing loss. Once hearing is gone, it’s gone forever.

Noise-induced hearing loss is a concern not only because it makes conversation and other daily activities more difficult, but also because it causes many other health problems. Exposure to noise causes stress, anxiety, depression, high blood pressure, and heart disease.

Even though noise is all around us, much hearing loss from noise is preventable. And the steps to protect the ears and preserve hearing are relatively simple and don’t cost much.

  • Avoid noisy places whenever possible.
  • If you must be in a noisy environment, step away from the sound source, and try to minimize the amount of time spent there.
  • Use earplugs, as a convenient, low-cost form of protection. Or use protective earmuffs or noise-canceling headphones.
  • At home and in the car, keep the volume down. And even though the evidence is mixed about using earbuds or headphones for listening, it’s still smart to keep the volume down and take breaks from listening.
  • People who know they’ve been exposed to loud noise, or who are concerned that they aren’t hearing as well as they used to can ask their doctors for a hearing checkup.

Clinicians, especially primary care providers, can play an important role in identifying hearing in its early stages. Doctors, nurses, and other health professionals can ask patients about exposure to loud noise and trouble hearing during routine exams. When patients show or report hearing problems, healthcare providers can make referrals to hearing specialists. And they can explain how noise exposure permanently damages hearing and counsel patients in how to protect their hearing.

For more information about noise-induced hearing loss, see

Exposure to a Newer Flame Retardant Has Been on the Rise

Out of concern that flame retardants—polybrominated diphenyl ethers (PBDEs)—cause health problems, the U.S. government worked with manufacturers to start phasing them out in 2004. But evidence has been building that PBDE replacements, including organophosphate flame retardants, are in the environment and in our bodies. Now researchers report—"Temporal Trends in Exposure to Organophosphate Flame Retardants in the United States"—in ACS’ journal Environmental Science & Technology Letters that exposure to at least one of the newer compounds has increased significantly over the past decade.

Through multiple studies over the past five years, Heather M. Stapleton and colleagues have found that organophosphates are among the most commonly detected flame retardants in furniture and electronics. The compounds are also used in many other products such as plastics and nail polish. Like their predecessors that are being phased out, organophosphates aren’t bound to products and can migrate out and accumulate in indoor air and in dust, on floors and on other surfaces. They can then get ingested, inhaled or even potentially absorbed through the skin. Stapleton’s lab has documented through several studies that the metabolites of organophosphate flame retardants are frequently showing up in urine. But these were all snapshots in time. To determine if there were any trends in exposure over several years, the researchers compiled the data from 14 of these studies that collected data between 2002 and 2015.

The researchers found that a metabolite of one commonly used organophosphate flame retardant, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), occurred at levels 15 times higher in 2014-2015 samples than in samples from 2002-2003. The analysis also suggested that exposure increases in the summer. The researchers say further research is needed to determine whether these levels are related to health problems.

The authors acknowledge funding from the National Institute of Environmental Health Science, the U.S. Environmental Protection Agency, the Duke University School of Medicine, and the Duke Nicholas School of the Environment.

New CDC Communication Tool for Radiation Emergencies

The Centers for Disease Control and Prevention (CDC) has developed a new tool for public health officials to communicate with the public in a radiation emergency. The Radiation Hazard Scale helps people better understand their risk for health effects from the emergency, and can encourage people to follow recommended protective actions if needed and reduce their risk. The tool is a scale of hazard levels, similar to other scales people are familiar with (e.g., hurricane categories). It describes the immediate potential impact of the accident for people, and the hazard category depends on where people are located.

Oregon OSHA Adopts Pesticide Rules

The Oregon Occupational Safety and Health Division (Oregon OSHA) will adopt most of a set of updated pesticide rules, to protect Oregon farm workers and those who handle pesticides.

The rules, proposed in 2016, are a result of updates to the EPA Worker Protection Standard. The updated standards affect areas such as training, pesticide labeling, and respiratory and emergency eye-washing requirements.

Another area addressed in the rules is protecting occupants of farm labor housing when pesticides are sprayed on nearby crops. Oregon OSHA received a significant amount of public comment about its proposal to protect these workers, and, as a result, it will kick off a new rulemaking early this year to revisit that issue.

The rules will take effect January 1, 2018, to allow time for the additional rulemaking process and transition to the new standards.

“A lot of stakeholders have put in a lot of time and hard work to get the new Worker Protection Standard right,” said Oregon OSHA Administrator Michael Wood. “We’ve received a range of public testimony and concerns. While we believe we’re nearly there, we do have some more work to do to make sure we get this right.”

In adopting most of the rule updates, Oregon OSHA is moving forward with several changes it introduced to reflect the unique circumstances for employers in Oregon, as well as embracing changes initiated by the EPA. It also made some adjustments based on public comments. For example, it streamlined the proposed training requirements for licensed trainers of pesticide handlers, based on feedback from the industry.

Oregon OSHA will re-convene the Small Agricultural Employer Advisory Committee to further review how to best protect farm labor housing occupants from pesticides. The committee includes representatives of labor, employers, grower organizations, and government and nonprofit agencies.

Oregon OSHA will ask the committee to focus on the specific issues involving the EPA-designated Application Exclusion Zone (AEZ). The zone surrounds and moves with certain pesticide-spray equipment during applications and must be free of all people other than appropriately trained and equipped pesticide handlers.

Oregon OSHA proposed a compliance alternative to the EPA’s requirement that everyone be evacuated from the zone during outdoor pesticide applications. That alternative is commonly known as “shelter in place.” It would allow occupants of protected spaces—including fully enclosed housing—to remain indoors as protection from the potential hazard of spray drift as the zone created by pesticide-spray equipment in a nearby crop area passes by. Oregon OSHA would like the advisory committee to consider whether there are ways to strengthen not only the shelter in place alternative, but also the underlying exclusion zone requirement.

Oregon OSHA will ask the advisory committee to work with the agency on new draft language so the agency can re-propose the rule in time for it to take effect with the other revised sections of the WPS on January 1, 2018. For more information about the advisory committee is on our advisory committee page.

For more information about WPS and related rules, visit our Worker protection standard topic page.

Alaska Occupational Safety and Health Fines North Country Services $280,000

The Alaska Department of Labor and Workforce Development has issued four citations against contractor North Country Services and fined the company $280,000 for willful violations of Alaska’s safety standards that resulted in a man’s death.

On September 30, 2016, Nicholson Tinker, age 24, was killed when a concrete retaining wall he was preparing for demolition collapsed, crushing him. The department determined that his employer and sole proprietor of North Country Services, Mark Welty, failed to conduct the required engineering survey to determine the state of the structure and the possibility of an unplanned collapse before demolition. The department also determined that Mr. Welty failed to ensure the structure was braced or stabilized against such a collapse despite clear indications the wall was damaged. Furthermore, Mr. Welty provided no safety training or instructions to his employees.

The department’s investigation found that Mr. Welty misclassified his employees as independent contractors, allowing him to evade the responsibility that all employers have to provide employees a workplace free of recognized hazards. Through misclassification, Mr. Welty also avoided paying unemployment insurance, taxes, and workers’ compensation premiums, further burdening law-abiding and responsible employers. Misclassification occurs when an employer improperly labels workers as independent contractors rather than as employees.

“This tragic case illustrates the toll that misclassification can take on workers,” said Labor Commissioner Heidi Drygas. “If Nicholson Tinker had been afforded the protections he deserved as an employee, he would be alive today.”

Worker misclassification is especially prevalent in the construction industry, where some contractors seek to undercut competition by reducing their labor costs. Misclassified workers are left without basic safety and health protections that are afforded to employees. These workers and their families may face financial ruin when they are injured on the job and left without basic workers’ compensation benefits.

CSB Investigators Deployed Explosion Investigation Team at Packaging Corporation of America

A three-person investigative team from the U.S. Chemical Safety Board (CSB) deployed to the scene of an incident that killed three workers and reportedly injured seven on Wednesday, February 8 at the Packaging Corporation of America (PCA) plant in DeRidder, Louisiana.

According to initial reports, the explosion took place while contractors performed welding on a tank during a facility shut down. The explosion was powerful enough to cause the tank to fly and land in a different area of the plant. Welding is one of several types of “hot work”—or spark-producing operations—that can ignite fires or explosions. Most hot work incidents result in the ignition of combustible materials or the ignition of structures or debris near the hot work.

“The CSB has investigated many hot work accidents across the country, including a 2008 explosion that killed three workers at a different PCA plant in Tomahawk, Wisconsin.” said Chairperson Vanessa Sutherland. “Hot work incidents are one of the most common causes of worker deaths we see at the CSB, but also one of the most readily preventable.”

Following the deadly 2008 explosion at the PCA plant in Wisconsin, the CSB issued a safety bulletin on the hazards of welding and other hot work entitled “Seven Key Lessons to Prevent Worker Deaths during Hot Work In and Around Tanks.” The agency also released a safety video called “Dangers of Hot Work,” which presents the findings from that bulletin.

Chairperson Sutherland said, “The CSB continues to be concerned about the frequency of dangerous hot work incidents and has added safe hot work practices to the agency’s Drivers of Critical Chemical Safety Change Program, a list of key chemical safety advocacy initiatives.”

The CSB is an independent federal agency whose mission is to drive chemical safety change through independent investigations to protect people and the environment. The agency’s board members are appointed by the President and confirmed by the Senate. CSB investigations look into all aspects of chemical incidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.

Westwind Construction, TraverseCONNECT, and MIOSHA Partner to Safeguard Workers

Westwind Construction, TraverseCONNECT, and the Michigan Occupational Safety and Health Administration (MIOSHA) recently signed a formal partnership with the goal of zero worker injuries, accidents and near misses during the construction of the Trailside45 apartment community in Traverse City.

Construction siteTrailside45 is a new multi-family apartment community under construction by Midwest Property Development, Inc., and Westwind Construction, a west Michigan commercial construction business with close ties to the Grand Traverse region. TraverseCONNECT has partnered with Westwind to make Trailside45 a reality for the Grand Traverse community. Construction began last November and is expected to be completed in the spring of 2018.

Located at Boyd and Garfield, the property incorporates 1.7 acres of long-time vacant land in the heart of Traverse City and will provide 74 residential units. The new housing will feature modern amenities consistent with urban living and will offer a welcoming community environment in the area for those in need of reasonably priced housing.

“We applaud Westwind for partnering with MIOSHA on this exciting project to achieve a significant and measurable reduction in workplace fatalities, injuries and illnesses,” said MIOSHA Director Bart Pickelman. “Together, we can have a greater impact on Michigan’s workplace safety and health.”

Signing partners include MIOSHA, TraverseCONNECT, Westwind and partnering subcontractors: Molon Excavating, Bay Masonry, Woods Carpentry and others. The partnership outlines clear safety objectives and provides analytics to help all parties improve their safety awareness with the ultimate goal of achieving zero recordable injuries and ensuring everyone returns home in the same condition they came to work in.

The safety of the construction project’s employees is fundamental to this partnership with MIOSHA. The leadership of Westwind, partnering contractors, and MIOSHA are aligned and committed to providing a workplace with an effective safety management system that is hazard-free. All partners agree to commit their leadership, time, and resources to reach this valuable goal.

“The Westwind family is honored and excited to partner with MIOSHA and trade contractors,” said Peter Oleszczuk, vice president of construction and one of the Westwind principals. “Project safety and awareness is critical to the successful completion of the Trailside45 project, as well as the growth and expansion of our industry. Westwind is proud to be an advocate for worker health and safety and is pleased to be able to demonstrate these values through this partnership agreement.”

Trailside45 derives its name from its close proximity to the Traverse Area Recreation Trail (TART), which runs adjacent to the development, making it convenient for residents to bike or walk to the downtown district. Residents can avoid the growing traffic congestion and easily enjoy the numerous amenities available in the surrounding area. The partnership does not preclude MIOSHA from enforcing its mission of addressing complaints, fatalities, or serious accidents, nor does it infringe on the rights of employees to report workplace hazards.

Two Michigan Companies Again Recognized by MIOSHA for Outstanding Workplace Safety and Health

Two Michigan companies have been awarded renewed status as Michigan Safety and Health Achievement Program worksites, the Michigan Occupational Safety and Health Administration (MIOSHA) announced recently.

Columbian Logistics Network—Grand Rapids Distribution Center and Saginaw manufacturer Glastender Incorporated were granted extensions in the MIOSHA program for maintaining outstanding workplace safety and health programs that far surpass their counterparts.

“Both Columbian and Glastender have engaged teams of employees that continue to show the utmost level of commitment to accident and illness prevention,” said MIOSHA Director Bart Pickelman. “MIOSHA is pleased to once again recognize these companies for prioritizing the safety of their workers.”

MIOSHA established the MSHARP to acknowledge employers and employees committed to creating a workplace culture that makes safety their top priority. The program targets small manufacturers to help them develop, implement and continuously improve the effectiveness of their workplace safety and health management system.

“At Columbian, safety is our number one value,” said Columbian Executive Vice President Robert Christian. “Achieving MSHARP status further underscores our ability to provide complete supply chain management solutions to our customers who entrust us with the safe and efficient handling of their goods.”

The program provides an incentive for employers to emphasize accident and illness prevention by anticipating problems, not reacting to them.

"We are honored to be recognized for our ongoing safety improvements,” said Glastender Vice President of Administration Kim Norris. “It is made possible by the commitment to safety our employees show each day and by the leadership provided from our safety administrator, Melvin Kuhl.”

MSHARP worksites earn an exemption from "programmed" MIOSHA inspections on a yearly basis.

Both facilities have an excellent safety and health management system in place, which incorporates each of the seven required elements: hazard anticipation and detection; hazard prevention and control; planning and evaluation; administration and supervision; safety and health training; management leadership; and employee participation.

Some of Columbian’s latest improvements include assigning chocks to each hi-lo truck to ensure trailers will be chocked before being loaded and unloaded, and adding blue lights to make the hi-los more visible to pedestrians and other hi-lo operators. Best practices for Glastender include new foaming fixtures and switching from wooden to steel carts to improve quality and safety.

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