Glyphosate exposure and preterm birth: A nested case-control pilot study.

Preterm birth (PTB) is associated with a high risk of infant mortality and long-term adverse health effects. Glyphosate is a broad-spectrum herbicide applied in agricultural and non-agricultural settings. Studies suggested an association between maternal exposure to glyphosate and PTB among mostly racially homogenous populations, though results were inconsistent. The objective of this pilot study was to inform the design of a larger and more definitive study of glyphosate exposure and adverse birth outcomes in a racially-diverse population. Urine was obtained from 26 women with a PTB as cases and 26 women with a term birth as controls, from participants enrolled in a birth cohort in Charleston, South Carolina. We used binomial logistic regression to estimate associations between urinary glyphosate and the odds of PTB, and multinomial regression to estimate associations between maternal racial identity and urinary glyphosate among controls. Glyphosate was unrelated to PTB (odds ratio (OR) = 1.06, 95% CI: 0.61, 1.86). Women who identified as Black had greater odds (OR = 3.83, 95% CI: 0.13, 111.33) of having categorical "high" glyphosate (> 0.28 ng/mL) and lesser odds (OR = 0.79, 95% CI: 0.05, 12.21) of "low" glyphosate (< 0.03 ng/mL) relative to women who identified as white, suggesting a potential racial disparity, although the effect estimates were imprecise and included the null. Given concerns of potential reproductive toxicity of glyphosate, the results merit confirmation in a larger investigation to determine specific sources of glyphosate exposure, incorporating longitudinal urinary glyphosate measures during pregnancy and a comprehensive measure of diet.

How are adolescents getting their vaping products? Findings from the international tobacco control (ITC) youth tobacco and vaping survey.

OBJECTIVE: To examine the sources of vaping products reported by adolescents, and the characteristics of adolescents who reported purchasing a vaping product in the past year in the United States (US), Canada (CA), and England (EN). METHODS: Data were from the 2017 ITC Youth Tobacco and Vaping Survey, a web-based survey of 12,128 respondents aged 16-19 years recruited from commercial panels in the US, CA, and EN. Respondents who have vaped in the past 12 months were asked whether they had purchased a vaping product, and from where (vape shop, online, retail), as well as whether anyone refused to sell them a vaping product because of their age. Respondents who reported vaping in the past 30 days were asked where they had obtained their vaping product from a social and/or commercial source. RESULTS: Only about 7.5% of respondents reported having purchased a vaping product in the past year. Among those who had vaped in the past year, 32.6% reported having purchased a vaping product in the past year. Purchasing prevalence was significantly higher among US respondents compared to those from CA and EN; purchase prevalence was also higher among Canadian adolescents than respondents from England. The most commonly reported purchase location for vaping products in all counties was vape shops. Among past 30-day vapers, 42.5% reported getting their vaping products only from social sources, 41.4% only from commercial sources, and 13.4% from both types of sources. Purchasing a vaping product in the past year was associated with being male, of legal age to buy tobacco and vaping products, and greater frequency of smoking and vaping in the past 30 days. CONCLUSIONS: Most adolescents have not purchased a vaping product, but among those who had, vape shops were the mostly commonly reported location for buying a vaping product. Purchasing of a vape product was more commonly reported by those who vape more frequently and by those of legal age to buy a vaping product.

Rules about smoking and vaping in the home: findings from the 2016 International Tobacco Control Four Country Smoking and Vaping Survey.

AIMS: To examine rules about smoking and vaping in the home in relation to beliefs about the relative harm of second-hand vapor (SHV) compared with second-hand smoke (SHS) in four countries: Canada, United States, England and Australia. DESIGN: Data were available from 12 294 adults (18+) who participated in the 2016 (wave 1) International Tobacco Control Four Country Smoking and Vaping (ITC 4CV1) Survey. PARTICIPANTS: All participants were current or recent former adult smokers. MEASUREMENTS: Data were analyzed by weighted logistic regression on rules about smoking and vaping in the home; odds ratios and 95% confidence intervals were reported, adjusted for demographic and behavioral variables. FINDINGS: Of all respondents, 37.4% allowed smoking inside their home. Among a subset who were current vapers (n = 6135), 60.4% allowed vaping in their homes. After controlling for demographic and behavioral characteristics, beliefs about the harm of SHV compared with SHS was not associated with allowing smoking in the home, but was associated with allowing vaping in the home [odds ratio (OR) = 2.86 in Canada, OR = 1.82 in the United States and OR = 1.68 in England]. Characteristics that were associated with rules about vaping inside the home included daily vaping (OR = 2.95, 2.04-4.26; OR = 7.00, 4.12-11.87; OR = 5.50, 3.40-8.88; OR = 7.78, 1.90-31.80), living with a spouse who vapes (OR = 2.48, 1.54-3.98; OR = 2.69, 1.42-5.11; OR = 4.67, 2.74-7.95; OR = 21.82, 2.16-220.9) and living with children aged under 18 years (OR = 0.50, 0.37-0.68; OR = 0.89, 0.48-1.65; OR = 0.76, 0.53-1.09; OR = 0.26, = 0.11-0.61) in Canada, the United States, England and Australia, respectively. Similar characteristics were associated with rules about smoking inside the home. CONCLUSIONS: Among current and former smokers in 2016 in Canada, the United States, England and Australia, 37.4% allowed smoking in the home; 60.4% of current vapers allowed vaping. Both concurrent users and exclusive vapers were more likely to allow vaping than smoking inside the home. Allowing vaping inside the home was correlated with the belief that second-hand vapor is less harmful than second-hand smoke.

Where Do Vapers Buy Their Vaping Supplies? Findings from the International Tobacco Control (ITC) 4 Country Smoking and Vaping Survey.

Aim: This study examines where vapers purchase their vaping refills in countries having different regulations over such devices, Canada (CA), the United States (US), England (EN), and Australia (AU). Methods: Data were available from 1899 current adult daily and weekly vapers who participated in the 2016 (Wave 1) International Tobacco Control Four Country Smoking and Vaping. The outcome was purchase location of vaping supplies (online, vape shop, other). Adjusted odds ratios and 95% confidence intervals were reported for between country comparisons. Results: Overall, 41.4% of current vapers bought their vaping products from vape shops, 27.5% bought them online, and 31.1% from other retail locations. The vast majority of vapers (91.1%) reported using nicotine-containing e-liquids. In AU, vapers were more likely to buy online vs other locations compared to CA (OR = 6.4, 2.3⁻17.9), the US (OR = 4.1, 1.54⁻10.7), and EN (OR = 7.9, 2.9⁻21.8). In the US, they were more likely to buy from vape shops (OR = 3.3, 1.8⁻6.2) or online (OR = 1.9, 1.0⁻3.8) vs other retail locations when compared to those in EN. In CA, vapers were more likely to purchase at vape shops than at other retail locations when compared to vapers in EN (5.9, 3.2⁻10.9) and the US (1.87, 1.0⁻3.1). Conclusions: The regulatory environment and enforcement of such regulations appear to influence the location where vapers buy their vaping products. In AU, banning the retail sale of nicotine vaping products has led vapers to rely mainly on online purchasing sources, whereas the lack of enforcement of the same regulation in CA has allowed specialty vape shops to flourish.

Adolescent mice are less sensitive to the effects of acute nicotine on context pre-exposure than adults.

Adolescence is a critical developmental period associated with both increased vulnerability to substance abuse and maturation of certain brain regions important for learning and memory such as the hippocampus. In this study, we employed a hippocampus-dependent learning context pre-exposure facilitation effect (CPFE) paradigm in order to test the effects of acute nicotine on contextual processing during adolescence (post-natal day (PND) 38) and adulthood (PND 53). In Experiment 1, adolescent or adult C57BL6/J mice received either saline or one of three nicotine doses (0.09, 0.18, and 0.36mg/kg) prior to contextual pre-exposure and testing. Our results demonstrated that both adolescent and adult mice showed CPFE in the saline groups. However, adolescent mice only showed acute nicotine enhancement of CPFE with the highest nicotine dose whereas adult mice showed the enhancing effects of acute nicotine with all three doses. In Experiment 2, to determine if the lack of nicotine's effects on CPFE shown by adolescent mice is specific to the age when they are tested, mice were either given contextual pre-exposure during adolescence or adulthood and received immediate shock and testing during adulthood after a 15day delay. We found that both adolescent and adult mice showed CPFE in the saline groups when tested during adulthood. However, like Experiment 1, mice that received contextual pre-exposure during adolescence did not show acute nicotine enhancement except at the highest dose (0.36mg/kg) whereas both low (0.09mg/kg) and high (0.36mg/kg) doses enhanced CPFE in adult mice. Finally, we showed that the enhanced freezing response found with 0.36mg/kg nicotine in the 15-day experiment may be a result of decreased locomotor activity as mice that received this dose of nicotine traveled shorter distances in an open field paradigm. Overall, our results indicate that while adolescent mice showed normal contextual processing when tested both during adolescence and adulthood, they are less sensitive to the enhancing effects of nicotine on contextual processing.

Concentration- and age-dependent effects of chronic caffeine on contextual fear conditioning in C57BL/6J mice.

Chronic caffeine exerts negligible effects on learning and memory in normal adults, but it is unknown whether this is also true for children and adolescents. The hippocampus, a brain region important for learning and memory, undergoes extensive structural and functional modifications during pre-adolescence and adolescence. As a result, chronic caffeine may have differential effects on hippocampus-dependent learning in pre-adolescents and adolescents compared with adults. Here, we characterized the effects of chronic caffeine and withdrawal from chronic caffeine on hippocampus-dependent (contextual) and hippocampus-independent (cued) fear conditioning in pre-adolescent, adolescent, and adult mice. The results indicate that chronic exposure to caffeine during pre-adolescence and adolescence enhances or impairs contextual conditioning depending on concentration, yet has no effect on cued conditioning. In contrast, withdrawal from chronic caffeine impairs contextual conditioning in pre-adolescent mice only. No changes in learning were seen for adult mice for either the chronic caffeine or withdrawal conditions. These findings support the hypothesis that chronic exposure to caffeine during pre-adolescence and adolescence can alter learning and memory and as changes were only seen in hippocampus-dependent learning, which suggests that the developing hippocampus may be sensitive to the effects of caffeine.