Latest blog entries All blog entries from Thu, 21 Sep 2017 01:22:40 +0000 en-gb Vaping of Alcohol – What are the Effects on Blood Alcohol Concentration?

Posted on behalf of Josh Maskrey.

A recent evaluation by Cardno ChemRisk scientists assessed the best practices for determining blood alcohol concentration (BAC) at specific time-points following alcohol ingestion (Cowan et al. 2016). While alcohol consumption via ingestion has been well characterized, other routes of exposure, such as inhalation, have become increasingly popular (CBS News 2013).

Alcohol inhalation via a vaporization device (“vaping”) has received substantial news coverage in the past five years (
Huffington Post 2013; 2015; Daily Herald 2017). Alcohol vaping typically involves heating a wine or spirit in a closed container until the majority of the liquid evaporates and then inhaling the resulting vapor. As of 2017, 24 states have banned the sale, purchase, or use of alcohol vaporizing devices as a direct result of this perceived hazard, and five further states have restricted using these devices in commercial establishments (NAMSDL 2014). To date, very few scientific or peer-reviewed assessments of alcohol inhalation and its potential health risks exist. Stogner et al. (2014) performed a large-scale study of innovative alcohol use in young adults in the USA and concluded that alcohol inhalation, along with other alternative consumption methods, was relatively rare among members of that group. In a recent critical review, MacLean et al. (2017) performed a thorough review of the literature and found that many peer-reviewed studies focus on low-concentration occupational ethanol exposure or vapor inhalation from hand sanitizers. They concluded that acute alcohol inhalation exposure and the effects of repeated exposure to large alcohol doses remain to be characterized. In alcohol vaporization scenarios, a user may be exposed to a concentration of 50-60% alcohol in air over a period of one to four seconds. These vaping exposure scenarios differ greatly from low-intensity worker or consumer exposures over longer durations as previously described (Bruckner and Warren 2001; Dumas-Campagna et al. 2014; Nadeau et al. 2003).

Toxicologists often describe the kinetics of drug use in terms of “ADME” – absorption, distribution, metabolism, and excretion. Deliberately concentrating and inhaling alcohol vapor is fundamentally distinct from drinking alcohol, in that the absorption kinetics will be much faster via the inhalation route. Because of the faster absorption kinetics associated with inhalation, a potential exists for both a higher maximum BAC and a shorter time to reach the maximum BAC via inhalation as compared to ingestion.

The distribution, metabolism, and excretion of alcohol should be identical for both the inhalation and ingestion routes. BAC as a function of time after inhaling very high ethanol concentrations over very short exposure times has not been adequately studied to date; a quantitative description of this relationship would be useful for forensic practitioners and toxicologists, as doing so would fill a data gap in the current state of knowledge.

Cardno ChemRisk’s team of toxicologists and health risk assessment professionals have conducted research into the toxicology and kinetics of alcohol in the body following ingestion. Our primary areas of expertise include forensic modeling of BAC over time using the Widmark approach and PBPK approaches, as well as best practices for factoring changes in postmortem blood alcohol concentration into a forensic analysis. If you would like to learn more about our areas of expertise in drug and alcohol pharmacokinetics and forensic toxicology, please contact
Dr. Ernest Fung.

]]> (Lindsey Garnick) Centers of Excellence Wed, 20 Sep 2017 20:55:09 +0000
Cardno ChemRisk Lead in Wine Paper Ranked in Top Three Accessed Articles

Cardno ChemRisk’s publication “A human health risk assessment of lead (Pb) ingestion among adult wine consumers” was recently named one of the top three highly accessed articles in the International Journal of Food Contamination.  Cardno ChemRisk scientists analyzed Pb concentration in wines and modeled adult blood lead levels from wine consumption under various exposure scenarios based on national dietary survey data. Overall, our findings suggest that Pb content in wine does not pose a health risk to adult wine consumers.  You can read our original blog about this paper here.

]]> (Melanie Nembhard) Centers of Excellence Fri, 15 Sep 2017 23:15:08 +0000
Cardno ChemRisk Attends the 2017 DIOXIN Symposia – Focus on PFAS Posted on behalf of Angela Perez, Paul Scott and Andrew Monnot.

The per- and polyfluoroalkyl substances, or PFASare a family of perfluorinated and polyfluorinated chemicals that have been used extensively since the 1950s in commercial applications, including surfactants, lubricants, paper and textile coatings, polishes, food packaging, and fire-fighting foams. Some of these PFAS, including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), persist in humans and the environment, and have been detected worldwide in wildlife. 

Two senior toxicologists at Cardno ChemRisk, Drs. Angie Perez and Andy Monnot, presented research on key PFAS exposure and risk assessment issues at the 2017 International DIOXIN Symposia, held in Vancouver, Canada from August 21 -25th.  Dr. Perez presented a meta-analysis of crop uptake factors for PFAS. The objective of Dr. Perez’s research was to provide a state-of-the science review on PFAS uptake in plants intended for human and animal consumption, and to conduct a screening level human health risk assessment for consumption of PFAS based on the following: i) in which crops PFASs have been detected; ii) at what concentrations are PFASs detected; iii) which PFASs have been previously detected in crops; and iv) where in the plant PFASs tend to accumulate, if at all. Additionally, known sources of PFAS deposition in soil and anticipated source deposition trends, based on commercial use patterns, were described.

Dr. Monnot presented a poster entitled An Evaluation of Federal and State Perfluorooctanoic acid (PFOA) Drinking Water Standards in the US.  The purpose of this research was to compare the federal and state drinking water standards for PFOA in light of the recent US EPA lifetime drinking water Health Advisory for PFOA of 0.01 µg/L.  A total of 10 PFOA drinking water standards were identified, ranging from 0.014 to 1.6 µg/L.  Each state used a variety of different assumptions to derive its PFOA drinking water standards. We found that only rarely was there any attempt to evaluate background exposures to PFOA; instead, most states employed a single “default” relative source contribution (RSC) factor, which may over-estimate PFOA’s true background exposures.  

A third poster, authored by Paul K. Scott, a senior risk assessor and expert statistician at Cardno ChemRisk with over 26 years’ experience, was presented by Dr. Monnot and titled A Probabilistic Evaluation of the 2016 U.S. EPA Health Advisory for Perfluorooctanoic Acid. The purpose of this analysis was to determine if some of the factors used to derive the US EPA health advisory for PFOA resulted in an overestimation of exposure and subsequent risk.  Specifically, Scott et al. determined that the relative source contribution (RSC) factor used by the US EPA is not consistent with the information in the scientific literature on background exposures to PFOA from non-drinking water sources. In this study, alternate values for the health advisory were calculated based on more realistic assumptions for the relative source contribution (RSC).  Using alternate values for the drinking water ingestion rate and the RSC resulted in health advisories for lactating women that ranged from 0.2 to 0.76 µg/L, and for the general population that ranged from 0.3 to 1.1 µg/L.  These results suggest that the US EPA used overly conservative assumptions when deriving its health advisory.

Cardno ChemRisk scientists have conducted numerous exposure studies and human health risk assessments pertaining to PFAS. Examples of Cardno ChemRisk’s key PFAS projects include a retrospective exposure assessment for PFOA; a critical review of the findings of the C8 Health Project panel; preparation of supporting documents for Canadian Soil Quality Guidelines; preparation of estimated daily intakes of PFAS from outdoor and indoor air, dust, soil, food, drinking water, and consumer products; and a hazard evaluation and human health risk assessment for a farm after 20 years of land application of biosolids. Cardno ChemRisk scientists also regularly present on the topic of PFAS. Recently, Dr. Perez presented a webinar with Earl Hagström of Sedgwick Law in San Francisco titled Beyond PFOA and PFOS — the Next Wave of Perfluorochemicals-Related Liability”. 

If you would like to learn more about our PFAS capabilities, please contact Paul Scott at or Angela Perez at  
]]> (Melanie Nembhard) Centers of Excellence Fri, 15 Sep 2017 22:54:49 +0000
Cardno ChemRisk Assists with Food Allergy Risk Assessments

Posted on behalf of Rachel Novick and Alison Bowman. 


Food allergens have continued to be a significant public health focus and there have been twelve major FDA food recalls for undeclared allergens in June 2017 alone (FDA). Allergies to nuts, milk, eggs, wheat, soy, and seafood have been increasing in recent decades and currently affect approximately three percent of the population in developed countries. Allergic reactions to foods include symptoms such as skin rashes, respiratory issues, gastrointestinal tract distress, and anaphylaxis. To avoid these reactions, the Food and Drug Administration's Food Allergen Labeling and Consumer Protection Act of 2004 requires food products sold in the United States to declare the presence of common food allergens on their product labels. Additionally, some producers may voluntarily declare that their product is produced on shared equipment with products containing food allergens or that it "may" contain certain allergens. However, inconsistencies in labeling can often leave consumers with food allergies uncertain about which warnings to heed and which products are safe for them. Unnecessary allergen declarations can needlessly restrict options for consumers with food allergies and a failure to properly declare allergens puts consumers at risk (Taylor et al. 2014). Cardno ChemRisk has assisted companies that experience cross contamination of milk and soy in determining the concentrations that are likely to pose an allergic risk to their consumers. If you have any questions or would like more information about this topic or related issues, please contact Rachel Novick at

]]> (Fian Louie) Centers of Excellence Fri, 04 Aug 2017 23:48:44 +0000
Cardno ChemRisk Analyzes the Risk of Autoimmune Disease Associated with Silicone Breast Implants Posted on behalf of Kevin Towle

Silicone breast implants have been used for augmentation or reconstructive breast surgeries since the 1960s. However, as their popularity skyrocketed, concerns began to arise regarding a potential link between the implants and autoimmune or connective tissue diseases. Numerous studies were conducted on this issue in the 1980s and beyond, yielding mixed results. In 1992, the FDA issued a moratorium on silicone implants for safety assessment, and this ban remained in effect until 2006. Today, silicone implants are used in 84% of breast augmentation surgeries. According to the American Society of Plastic Surgeons, there were approximately 243,600 silicone breast augmentations in 2016.

During the FDA's moratorium, in 2000, a meta-analysis was conducted that examined 20 studies between 1984 and 1999. This analysis found no association between silicone breast implants and autoimmune disease. Since then, tools for autoimmune disease diagnosis have improved. Subsequent studies utilizing these tools found positive associations in previously unexamined cohorts, which demonstrated a need for an updated meta-analysis to quantitatively measure any association between silicone implants and autoimmune disease.

In 2016, Cardno ChemRisk conducted a meta-analysis of the results of 20 cohort and nine case control studies. Silicone breast implants were associated with a non-statistically significant decreased risk for all connective tissue diseases, meta-RR 0.87 (95% CI: 0.62-1.21). When stratified by disease, silicone breast implants were associated with a non-statistically significant increased risk of sclerosis, meta-RR 1.14 (0.75-1.74), and a non-statistically significant decreased risk of rheumatoid arthritis, meta-RR 0.75 (95% CI: 0.52-1.08), and systemic lupus erythematosus, meta-RR 0.90 (95% CI: 0.43-1.87). These findings suggest that silicone breast implant exposure is not associated with autoimmune disease among women.

If you would like to receive more information on this topic, please contact Dr. Andrew Monnot. ]]> (Luda Kopelovich) Centers of Excellence Wed, 26 Jul 2017 21:38:20 +0000