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Posted by on in Centers of Excellence
Posted on behalf of Elleen Hsu

Ms. Elleen Hsu recently presented a poster entitled “Insulation Usage and Asbestos Exposures: Historical Trends and Exposure Assessment” at the 2017 International Society of Exposure Science Meeting held in Durham, North Carolina. The purpose of this research was to identify factors that impacted the trends of historical airborne asbestos concentrations from insulation products and to model how these factors would affect human exposures. The authors found that airborne fiber concentrations measured during insulation work in shipyards were 3.5 to 15.5 times higher than concentrations measured for similar tasks in non-shipyard settings. The authors also modeled asbestos exposure estimates for full-shift insulators using task-specific frequencies and concentrations reported in the literature. Using our model, a cumulative occupational exposure for an insulator could be estimated by summing the cumulative exposure for the years of interest. Additionally, our research also found that asbestos concentrations declined over time, likely driven by the passage of the OSH Act and subsequent PEL rulings, as well as advancements in asbestos research and industrial hygiene practices.
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Posted by on in Centers of Excellence
Posted on behalf of Melinda Hoang

Acrylamide is a chemical primarily used in industrial processes for its water-soluble and thickening properties, such as in the manufacturing of paper and plastic and in treating drinking water and wastewater (Lineback et al. 2012).  In 1994, the International Agency for Research on Cancer (IARC) classified acrylamide as “probably carcinogenic to humans” (IARC 1994).  Acrylamide is characterized as being neurotoxic, and its main metabolite, glycidamide, has been associated with genotoxicity.  In 2002, the Swedish National Food Administration reported the presence of high acrylamide levels in certain types of food (Tareke et al. 2002).  Acrylamide is mainly formed as part of the Maillard reaction, in which reducing sugars such as glucose and fructose react with amino acids at temperatures above 120°C in thermal food treatments such as frying, baking, and roasting (Lineback et al. 2012).  Previous studies have reported cancer as well as reproductive and developmental effects in laboratory animals exposed to acrylamide, which led California to add acrylamide to its Prop 65 list of chemicals known to the state to cause cancer or reproductive toxicity. 

Acrylamide is currently receiving widespread attention in media reports due to its formation in coffee.  Many studies have analyzed acrylamide levels in different brands and types of coffee as well as potential factors that may affect acrylamide levels in coffee, such as the coffee variety, ripeness of the coffee bean, roasting process, and storage conditions (Alves et al. 2010; Lantz et al. 2006).  However, very few studies have estimated the potential acrylamide exposure from daily intake of coffee, and even fewer studies have conducted a human health risk assessment to determine the potential cancer risk from lifetime exposure to coffee.

In 2004, the U.S. FDA published an article reporting acrylamide levels in brewed coffee; however, the agency did not estimate U.S. consumers’ total daily intake of acrylamide or calculate their potential risk from lifetime exposure based on these numbers (Andrzejewski et al. 2004).  Since then, many new coffee products and non-traditional brewing methods have entered the market and gained popularity in the U.S.  While quantitative risk assessments of traditional coffee products have been conducted for populations outside the U.S., there remain data gaps for quantifying acrylamide in key coffee products distributed within the U.S., and for understanding the risk of cancer associated with exposure to these products. 

Cardno ChemRisk has assessed human exposure to many different chemicals in consumer products.  Our exposure assessment specialists are able to estimate the exposure and characterize the potential health risks associated with acrylamide exposure via coffee consumption.  If you would like to learn more about our capabilities or have any questions about this topic, please contact Rachel Novick at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .  
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Posted by on in Centers of Excellence
Posted on behalf of Suren Bandara.

Who is affected?

In the last couple of weeks, California has seen the most lethal outbreak of wildfires in the state’s history (CNBC 2017). The huge wildfires swept across Sonoma, Napa and Mendocino counties, sending smoke and ash over San Francisco (about 50 miles away) and to some towns and cities even further away. While the wildfires are being controlled, concerns over the wildfire smoke, which can persist for days or even months, depending on the extent of the fire, have arisen. Although the air may look clear, it may have particulate matter than can cause respiratory distress. Anyone who spends time outdoors during and after a wildfire can be affected by poor air quality, and outdoor workers are especially vulnerable.

Health basis

According to the Centers for Disease Control and Prevention (CDC), wildfire smoke is a mix of gases and fine particles from burning vegetation, building materials, and other materials (CDC 2017). This complex mixture resulting from combustion may contain carbon dioxide, water vapor, carbon monoxide, hydrocarbons and other organic chemicals, nitrogen oxides, trace minerals, and particulate matter (USEPA 2016). Outdoor workers exposed to these compounds via wildfire smoke inhalation might be at risk of developing mild to severe health symptoms, including difficulty breathing, scratchy throat, runny nose, irritated sinuses, reduced lung function, asthma attacks, chest pain, heart failure, or even death (CDC 2017, USEPA 2016). Persons with preexisting pulmonary and cardiovascular conditions may be more likely to get sick if they breathe in wildfire smoke (USEPA 2016).

Precautions employers can take

According to the US EPA, particulate matter is the principal pollutant of concern for persons exposed to wildfire smoke. Particulate matter larger than 10 mm do not usually reach the lungs, but may irritate the eyes, nose, and throat. However, wildfire smoke may contain particulates that are <10 mm, which can be inhaled into the deepest recesses of the lungs and can affect both the lungs and heart (USEPA 2016). Fortunately, steps can be taken to avoid particulate inhalation from wildfire smoke exposure.

NIOSH recommends that persons working outdoors should don two-strap N95 particulate filtering facepiece respirators (which capture 95% of very small particles) or respiratory protection devices with a higher level of protection, such as a P100 respirator (which capture 99.97% of very small particles). A full list of NIOSH approved N95 masks listed by manufacturer can be found here.

NIOSH warns that respirators and surgical masks are designed for different functions, and do not provide the same types or level of protection. Paper “comfort” or “dust” masks commonly found at hardware stores are designed to trap large particles, such as sawdust (NIOSH 2017). Therefore, these masks will not protect your lungs from the small particles found in wildfire smoke.

According to NIOSH, you should limit the amount of vigorous activity outdoors when wildfire smoke is suspected. Individuals traveling in vehicles in the vicinity of wildfire smoke should close all windows and make sure air conditioning is set to ‘re-circulate’ mode (USEPA 2016).

Persons working in office and commercial buildings can also be exposed to the hazards of windborne wildfire smoke. Unlike in the home environment, where setting air conditioners to recirculation mode is advised, workers in office spaces or commercial buildings with HVAC systems are advised against eliminating or substantially reducing the outdoor air supply to the building (Cal/OSHA 2008). HVAC systems in office buildings typically filter and condition outdoor air, and often have exhaust systems that require makeup air from outdoors. HVAC systems should thus be operated continuously to provide the minimum quantity of outdoor air for ventilation in accordance with standards and building codes. According to California OSHA, to protect building occupants from outdoor air pollution, building managers and employers should ensure that the HVAC systems’ filters are not dirty, damaged, dislodged, or leaking around the edges, and make necessary repairs as required (Cal/OSHA 2008).  

Additionally, California OSHA encourages employers to take steps to reduce employee exposure to smoke, including, alternate work assignments and telecommuting. In buildings that lack a functioning filtration system that removes particulates from the air, employers are encouraged to provide relocation options for employees (Cal/OSHA 2008).

To get real-time data on current air quality in your area, visit the U.S. Environmental Protection Agency’s (EPA’s) website. In addition, information is available from the CDC on protecting fire cleanup workers (here) and on well-being after a wildfire (here).

Cardno ChemRisk scientists have evaluated regulatory benchmarks and the underlying scientific literature regarding potential human health effects from particulate matter or other components of smoke, either from air pollution or wildfires. Cardno ChemRisk has a number of industrial hygienists and environmental health professionals who can assess exposure and risk of adverse health effects in specific settings. If you have any questions, or would like more information about our environment, health, and safety capabilities, please contact William Cyrs, CIH, at This e-mail address is being protected from spambots. You need JavaScript enabled to view it
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Posted by on in Centers of Excellence
Posted on behalf of Lauren Gloekler.

A group of flame-retardant chemicals called polybrominated diphenyl ethers (PBDEs) have been produced in various commercial mixtures, commonly referred to as pentaBDE, octaBDE, and decaBDE (EPA 2017). These chemicals are associated with a variety of adverse health outcomes associated with IQ development, attention span, memory, and mental processing speed (Guardian 2017). Although these chemicals were voluntarily phased out in the U.S. by top manufacturers in 2004 and in 2013, they continue to be imported and found in consumer products sold in the U.S. (EPA 2017Furniture World 2004Baschuk 5/2017). Electronics recycling, or “e-waste,” can result in the PBDEs found in electronics being preserved in the plastics used in new consumer products, such as children’s toys (PR Newswire 2017Brewerton 2017). Countries like China are involved in huge e-waste recycling activities, and in 2010 Chinese imports represented 88% of all toys imported into the U.S. (Guardian 2017, U.S. Dept of Commerce 2012). 

Under the EU’s REACH law, decaBDE will be “largely prohibited” in the EU after March 2, 2019 (Gardner 2017).  In October, 2016, decaBDE was added the PBT list of chemicals to be evaluated by the U.S. EPA, under the new TSCA reform (Rizzuto 2016Parker 2016). An EPA decision regarding decaBDE is due by June, 2019 (Parker 2016). In May, 2016, the Stockholm Convention agreed that decaBDE should be phased out and eventually banned; however, several exemptions may exist that allow these and other similar chemicals to continue to be used in certain applications (Baschuk 5/2017, Baschuk 1/2017). The International POPs Elimination Network (IPEN) criticized the Stockholm decision, saying that the policy would still allow for decaBDE to be used in contaminated recycling streams, and thus in children’s toys (Baschuk 5/2017).

Several studies have confirmed the presence of PBDEs in children’s toys from China (Chen et al. 2009IPEN 2017). According to a 2017 IPEN survey, several children’s toys from 26 countries (many of which were purchased in China) were sampled for octaBDE and decaBDE (IPEN 2017). Ninety-one percent of the samples contained decaBDE, ranging from 1 ppm to 672 ppm, 43% of which were at levels higher than 50 ppm. Another study by Chen et al. measured much lower concentrations in 69 toys purchased from China; decaBDE was found in mean levels between 0.0003 ppm and 0.20 ppm in toys, with variation between the toy types (hard plastic vs. foam, etc.) (Chen et al. 2009). The authors concluded that the profiles of brominated flame retardants measured in the toys were “consistent with the patterns of their current production and consumption in China” (Chen et al. 2009). They also estimated that daily exposure in children to decaBDE (pg/kg bw-day) was 0.55-2.06 via inhalation, 439-5001 via mouthing, 0.51-0.73 via dermal contact, and 0.03-0.52 via oral ingestion (hand-to-mouth). Total daily exposure via all routes was significantly lower than the EPA RfD (reference dose) for decaBDE (7 X 106 pg/kg bw-day), and the hazard quotient for decaBDE was well below one (EPA 2009). The authors thus concluded that the data suggested a low risk of adverse health outcomes associated with children’s toys. Given that the IPEN study measured decaBDE in concentrations approximately 3,000 times higher than Chen et al., however, further study on the risk associated with decaBDE exposures in children from toys is warranted. 

Cardno ChemRisk has assessed human exposure to many chemicals (including phthalates and lead) in children’s products. Our exposure assessment specialists are able to estimate the exposure and the potential health risk from many consumer products and provide creative and pragmatic solutions. If you have any questions or would like more information about this topic or related issues, please contact Lauren Gloekler at This e-mail address is being protected from spambots. You need JavaScript enabled to view it or Rachel Novick at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
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Posted by on in Centers of Excellence

Posted on behalf of Angie Perez

As of August 15, 2017, 29 states and Washington, D.C. have passed laws that legalize medical marijuana, and recreational marijuana is legal in eight states and Washington, D.C. These policy changes present new challenges for state regulators with respect to potentially increased impaired driving associated with marijuana use. A major hurdle in enforcing driving impairment laws is the lack of a standardized, non-invasive test that can determine a driver’s level of intoxication and impairment. Several calls for research have been put forth by various states (e.g., California and Colorado), as well as federal agencies (including the National Institute on Drug Abuse and the National Highway Traffic Safety Administration) in order to assist in determining impairment levels from marijuana use. Two companies, Hound Labs and Cannabix Technologies, are racing to develop and market instruments for detecting THC in breath (breathalyzer). While both companies have demonstrated that their devices are capable of detecting THC in breath, many challenges still exist in terms of correlating the concentration measured in breath with a driver’s impairment level.

A recent article by Lovestead and Bruno (2017) presented a three-pronged research approach for developing the “best” breathalyzer. According to the authors, these three prongs include: 1) providing fundamental data and models for the developing a breathalyzer; 2) studying the material properties in order to identify the best materials to “catch” and “release” THC; and 3) researching the chemical signature of breath that corresponds with intoxication (Lovestead and Bruno 2017). The authors found that THC and CB vapor pressures were two orders of magnitude lower than n-eicosane, a similar molecular weight compound with low vapor pressure, indicating that using surrogate data in models would have led to erroneous results. Ultimately, this finding illustrates the importance of having accurate fundamental data for developing and validating models. In light of this paper’s findings, then, although marijuana breathalyzers are near completion, ultimately identifying and establishing an impairment level will still require much work.

Cardno ChemRisk is evaluating methods based on existing published studies to model and correlate marijuana biomarker concentrations in blood with known metrics for behavioral and physiomotor impairment. Such pharmacodynamics-pharmacokinetic modeling and a better understanding of thresholds for physiomotor impairment will provide state regulators and law enforcement the necessary tools for adequately establishing and enforcing threshold impairment laws. If you would like to learn more about either these research areas, or our expertise in drug and alcohol pharmacokinetics and forensic toxicology, please contact Dr. Angie Perez or Dr. Ernest Fung.

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Cardno ChemRisk is a respected scientific consulting firm headquartered in San Francisco with locations and consultants across the U.S. While our website provides a formal look at our capabilities, the Cardno ChemRisk View provides an informal voice too. Various Cardno ChemRisk consultants will be sharing news and views about current trends, happenings and methodologies in the industry. We’ll also highlight activities of interest at Cardno ChemRisk, within confidentiality restrictions of course.

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