Maternal exposure to pyrethroid insecticides during pregnancy and respiratory allergy symptoms among children participating in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE).

BACKGROUND: Pyrethroid insecticides use for indoor residual spraying (IRS) in malaria-endemic areas results in high levels of exposure to local populations. Pyrethroids may cause asthma and respiratory allergies but no prior study has investigated this question in an IRS area. METHODS: We measured maternal urinary concentrations of pyrethroid metabolites (cis-DBCA, cis-DCCA, trans-DCCA, 3-PBA) in samples collected at delivery from 751 mothers participating in the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE), a birth cohort study based in Limpopo, South Africa. At 3.5-year and 5-year follow-up visits, caregivers of 647 and 620 children, respectively, were queried about children's respiratory allergy symptoms based on validated instruments. We applied marginal structural models for repeated outcomes to estimate associations between biomarker concentrations and asthma diagnosis as well as respiratory allergy symptoms at ages 3.5 and 5 years. RESULTS: We found that a10-fold increase in maternal urinary cis-DCCA, trans-DCCA and 3-PBA concentrations were associated with more than a doubling in the risk of doctor-diagnosed asthma (cis-DCCA: RR = 2.1, 95% CI = 1.3, 3.3; trans-DCCA: RR = 2.1, 95% CI = 1.1, 3.9; 3-PBA: RR = 2.4, 95% CI = 1.0, 5.8) and an about 80% increase in the risk of wheezing or whistling in the chest (cis-DCCA: RR = 1.8, 95% CI = 1.1, 3.0; trans-DCCA: RR = 1.7, 95% CI = 1.1, 2.6; 3-PBA: RR = 1.8, 95% CI = 1.0, 3.3) and suspected asthma (cis-DCCA: RR = 1.8, 95% CI = 1.1, 3.1; trans-DCCA: RR = 1.8, 95% CI = 1.1, 2.8). We also observed that higher concentrations of cis-DBCA and 3-PBA were related to increases in the risks of dry cough at night (RR = 3.5, 95% CI = 1.3, 9.5) and seasonal rhinoconjunctivitis (RR = 2.0, 95% CI = 1.1, 3.9), respectively. CONCLUSION: Maternal exposure to pyrethroids may increase the risk of asthma and other respiratory allergy symptoms among preschool children from an IRS area.

Exposure to pesticides and risk of Hodgkin lymphoma in an international consortium of agricultural cohorts (AGRICOH).

PURPOSE: Some pesticides may increase the risk of certain lymphoid malignancies, but few studies have examined Hodgkin lymphoma (HL). In this exploratory study, we examined associations between agricultural use of 22 individual active ingredients and 13 chemical groups and HL incidence. METHODS: We used data from three agricultural cohorts participating in the AGRICOH consortium: the French Agriculture and Cancer Cohort (2005-2009), Cancer in the Norwegian Agricultural Population (1993-2011), and the US Agricultural Health Study (1993-2011). Lifetime pesticide use was estimated from crop-exposure matrices or self-report. Cohort-specific covariate-adjusted overall and age-specific (< 40 or ≥ 40 years) hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression and combined using random effects meta-analysis. RESULTS: Among 316 270 farmers (75% male) accumulating 3 574 815 person-years at risk, 91 incident cases of HL occurred. We did not observe statistically significant associations for any of the active ingredients or chemical groups studied. The highest risks of HL overall were observed for the pyrethroids deltamethrin (meta-HR = 1.86, 95% CI 0.76-4.52) and esfenvalerate (1.86, 0.78-4.43), and inverse associations of similar magnitude were observed for parathion and glyphosate. Risk of HL at ≥ 40 years of age was highest for ever-use of dicamba (2.04, 0.93-4.50) and lowest for glyphosate (0.46, 0.20-1.07). CONCLUSION: We report the largest prospective investigation of these associations. Nonetheless, low statistical power, a mixture of histological subtypes and a lack of information on tumour EBV status complicate the interpretability of the results. Most HL cases occurred at older ages, thus we could not explore associations with adolescent or young adult HL. Furthermore, estimates may be attenuated due to non-differential exposure misclassification. Future work should aim to extend follow-up and refine both exposure and outcome classification.

Evaluation of Bayesian spatiotemporal infectious disease models for prospective surveillance analysis.

BACKGROUND: COVID-19 brought enormous challenges to public health surveillance and underscored the importance of developing and maintaining robust systems for accurate surveillance. As public health data collection efforts expand, there is a critical need for infectious disease modeling researchers to continue to develop prospective surveillance metrics and statistical models to accommodate the modeling of large disease counts and variability. This paper evaluated different likelihoods for the disease count model and various spatiotemporal mean models for prospective surveillance. METHODS: We evaluated Bayesian spatiotemporal models, which are the foundation for model-based infectious disease surveillance metrics. Bayesian spatiotemporal mean models based on the Poisson and the negative binomial likelihoods were evaluated with the different lengths of past data usage. We compared their goodness of fit and short-term prediction performance with both simulated epidemic data and real data from the COVID-19 pandemic. RESULTS: The simulation results show that the negative binomial likelihood-based models show better goodness of fit results than Poisson likelihood-based models as deemed by smaller deviance information criteria (DIC) values. However, Poisson models yield smaller mean square error (MSE) and mean absolute one-step prediction error (MAOSPE) results when we use a shorter length of the past data such as 7 and 3 time periods. Real COVID-19 data analysis of New Jersey and South Carolina shows similar results for the goodness of fit and short-term prediction results. Negative binomial-based mean models showed better performance when we used the past data of 52 time periods. Poisson-based mean models showed comparable goodness of fit performance and smaller MSE and MAOSPE results when we used the past data of 7 and 3 time periods. CONCLUSION: We evaluate these models and provide future infectious disease outbreak modeling guidelines for Bayesian spatiotemporal analysis. Our choice of the likelihood and spatiotemporal mean models was influenced by both historical data length and variability. With a longer length of past data usage and more over-dispersed data, the negative binomial likelihood shows a better model fit than the Poisson likelihood. However, as we use a shorter length of the past data for our surveillance analysis, the difference between the Poisson and the negative binomial models becomes smaller. In this case, the Poisson likelihood shows robust posterior mean estimate and short-term prediction results.

Prenatal Exposure to Insecticides and Weight Trajectories Among South African Children in the VHEMBE Birth Cohort.

BACKGROUND: Dichlorodiphenyltrichloroethane (DDT) or pyrethroid insecticides are sprayed inside dwellings for malaria vector control, resulting in high exposure to millions of people, including pregnant women. These chemicals disrupt endocrine function and may affect child growth. To our knowledge, few studies have investigated the potential impact of prenatal exposure to DDT or pyrethroids on growth trajectories. METHODS: We investigated associations between gestational insecticide exposure and child growth trajectories in the Venda Health Examination of Mothers, Babies and their Environment, a birth cohort of 751 children born between 2012 and 2013 in South Africa. Based on child weight measured at follow-up and abstracted from medical records, we modeled weight trajectories from birth to 5 years using SuperImposition, Translation and Rotation, which estimated two child-specific parameters: size (average weight) and tempo (age at peak weight velocity). We estimated associations between peripartum maternal concentrations of serum DDT, dichlorodiphenyldichloroethylene, or urinary pyrethroid metabolites and SuperImposition, Translation and Rotation parameters using marginal structural models. RESULTS: We observed that a 10-fold increase in maternal concentrations of the pyrethroid metabolite trans-3-(2,2,-dicholorvinyl)-2,2-dimethyl-cyclopropane carboxylic acid was associated with a 21g (95% confidence interval = -40, -1.6) smaller size among boys but found no association among girls (Pinteraction = 0.07). Estimates suggested that pyrethroids may be associated with earlier tempo but were imprecise. We observed no association with serum DDT or dichlorodiphenyldichloroethylene. CONCLUSIONS: Inverse associations between pyrethroids and weight trajectory parameters among boys are consistent with hypothesized disruption of androgen pathways and with our previous research in this population, and support the endocrine-disrupting potential of pyrethroids in humans.

Developmental and Momentary Dynamics in the Onset and Maintenance of Nonsuicidal Self-Injurious Behavior and Borderline Personality Disorder.

PURPOSE OF REVIEW: Traditional conceptualizations of both nonsuicidal self-injury (NSSI) and borderline personality disorder (BPD) typically rely on static and unidirectional, linear associations between key biopsychosocial vulnerabilities. Instead, we argue that utilizing a complex dynamic systems view of NSSI and BPD will advance the field, as such conceptual models allow for analysis of bottom-up effects for key vulnerabilities on disorder and behavior emergence, as well as top-down effects of the emergent disorder on underlying vulnerabilities. RECENT FINDINGS: Following the presentation of a novel framework highlighting momentary and developmental dynamics, we explore several advances in the field that exhibit key dynamic qualities or inform dynamic conceptualizations of NSSI and BPD. At the momentary dynamic level, several advances are being made with multimethod and repeated assessment approaches, as well as advanced bidirectional and complex modeling procedures. Additional progress is being made at the developmental dynamic level, although several questions have arisen regarding the problem of onset and subsequent trajectory, particularly with issues such as pain perception and the interplay between interpersonal, emotional, and behavioral symptoms before and after treatment. Self-injury and BPD both exhibit substantial momentary and developmental dynamics in underlying vulnerabilities, including potential variance in momentary dynamics as a function of psychopathological developmental stage (e.g., onset versus maintenance versus recovery). Recent work has highlighted the necessity of utilizing multimodal research to encapsulate a holistic view of the interplay of several vulnerability factors, the developmental importance of assessment timing, and the need to examine the dynamic interplay between affect, behavior, and interpersonal experiences in BPD and/or NSSI. Research also indicated substantial variation in key vulnerability factors at both between- and within-person levels, highlighting the utility of harnessing statistical models that allow for the simultaneous incorporation of numerous variables at both levels and across several time points. As such, by using a complex dynamic systems conceptualization, we can begin to better understand integrated connections between key vulnerabilities, how they collectively interact in the short term, and how changes in the dynamic interplay between vulnerabilities may arise over the long term and with successful treatment.

The Update Immune-Regulatory Role of Pro- and Anti-Inflammatory Cytokines in Recurrent Pregnancy Losses.

Recurrent pregnancy losses (RPL) is a common reproductive disorder with various underlying etiologies. In recent years, rapid progress has been made in exploring the immunological mechanisms for RPL. A propensity toward Th2 over Th1 and regulatory T (Treg) over Th17 immune responses may be advantageous for reproductive success. In women with RPL and animals prone to abortion, an inordinate expression of cytokines associated with implantation and early embryo development is present in the endometrium or decidua secreted from immune and non-immune cells. Hence, an adverse cytokine milieu at the maternal-fetal interface assaults immunological tolerance, leading to fetal rejection. Similar to T cells, NK cells can be categorized based on the characteristics of cytokines they secrete. Decidual NK (dNK) cells of RPL patients exhibited an increased NK1/NK2 ratio (IFN-γ/IL-4 producing NK cell ratios), leading to pro-inflammatory cytokine milieu and increased NK cell cytotoxicity. Genetic polymorphism may be the underlying etiologies for Th1 and Th17 propensity since it alters cytokine production. In addition, various hormones participate in cytokine regulations, including progesterone and estrogen, controlling cytokine balance in favor of the Th2 type. Consequently, the intricate regulation of cytokines and hormones may prevent the RPL of immune etiologies. Local or systemic administration of cytokines or their antagonists might help maintain adequate cytokine milieu, favoring Th2 over Th1 response or Treg over Th17 immune response in women with RPL. Herein, we provided an updated comprehensive review regarding the immune-regulatory role of pro- and anti-inflammatory cytokines in RPL. Understanding the roles of cytokines involved in RPL might significantly advance the early diagnosis, monitoring, and treatment of RPL.

Assessment of Practices Affecting Racial and Ethnic COVID-19 Vaccination Equity in 10 Large US Cities.

CONTEXT: In the United States, COVID-19 vaccines have been unequally distributed between different racial and ethnic groups. Public reporting of race and ethnicity data for COVID-19 vaccination has the potential to help guide public health responses aimed at promoting vaccination equity. However, there is evidence that such data are not readily available. OBJECTIVES: This study sought to assess gaps and discrepancies in COVID-19 vaccination reporting in 10 large US cities in July 2021. DESIGN, SETTING, AND PARTICIPANTS: For the 10 cities selected, we collected COVID-19 vaccination and population data using publicly available resources, such as state health department Web sites and the US Census Bureau American Community Survey. We examined vaccination plans and news sources to identify initial proposals and evidence of implementation of COVID-19 vaccination best practices. MAIN OUTCOME MEASURE: We performed quantitative assessment of associations of the number of vaccination best practices implemented with COVID-19 racial and ethnic vaccination equity. We additionally assessed gaps and discrepancies in COVID-19 vaccination reporting between states. RESULTS: Our analysis did not show that COVID-19 vaccination inequity was associated with the number of vaccination best practices implemented. However, gaps and variation in reporting of racial and ethnic demographic vaccination data inhibited our ability to effectively assess whether vaccination programs were reaching minority populations. CONCLUSIONS: Lack of consistent public reporting and transparency of COVID-19 vaccination data has likely hindered public health responses by impeding the ability to track the effectiveness of strategies that target vaccine equity.

Evaluation of NKp46 expression and cytokine production of decidual NK cells in women with recurrent pregnancy loss.

Purpose: NKp46, a receptor on NK cells, is involved in cytotoxicity and cytokine production. The authors aimed to evaluate the effect of NKp46 on decidual NK (dNK) cells during pregnancy and whether it can be a marker for immunological abnormalities in women with recurrent pregnancy loss (RPL). Methods: Flow-cytometric analysis was made to assess NKp46 expression and intracellular cytokine production of dNK cells. The proportion of NKp46+ dNK cells was analyzed among RPL patients who aborted karyotypically normal pregnancies and those who either aborted karyotypically abnormal pregnancies or without genetic studies, and controls who were going through the induced abortion. Results: The %NKp46+ and %NKp46bright dNK cells were significantly lower in the RPL women who aborted karyotypically normal pregnancies than in the control group. The %NKp46bright dNK cells were significantly correlated with the NK1/NK2 ratio of dNK cells. The %NKp46+ dNK cell cutoff for RPL with immunological abnormalities was determined by the ROC curve analysis. In women with the low %NKp46+ dNK, NK1/NK2 ratios were significantly higher than those with the high. Conclusion: RPL patients with an immunological abnormality have decreased NKp46 expression and NK1 shift in dNK cells. NKp46 expression could be a marker for RPL of immunological abnormalities.

Outcomes of Pregnancy During Immunotherapy Treatment for Cancer: Analysis of Clinical Trials Sponsored by the National Cancer Institute.

Despite expanding indications for immunotherapeutic agents, there is limited understanding about their clinical effects on pregnancy outcomes. Generally, pregnant patients with cancer are excluded from clinical trials, and inadvertent pregnancies on trial result in patients being taken off because of concerns for fetal toxicity. To answer this question of pregnancy outcomes on immunotherapy-based trials, we performed a retrospective analysis of the National Cancer Institute (NCI) Cancer Therapy Evaluation Program (CTEP)-Adverse Event Reporting System for unexpected pregnancies during NCI-CTEP-sponsored immunotherapy clinical trials between 2011 and 2020. We identified nine female patients who had unexpected pregnancies, of whom seven chose to take their pregnancies to term. All seven pregnancies resulted in vaginal births of apparently normal infants. This is the first report of pregnancy outcomes in multiple female patients exposed to immunotherapy. Our data suggest the need for further research to better evaluate and define contraception recommendations during immunotherapy treatment for cancer.

Predicting Energetics Materials' Crystalline Density from Chemical Structure by Machine Learning.

To expedite new molecular compound development, a long-sought goal within the chemistry community has been to predict molecules' bulk properties of interest a priori to synthesis from a chemical structure alone. In this work, we demonstrate that machine learning methods can indeed be used to directly learn the relationship between chemical structures and bulk crystalline properties of molecules, even in the absence of any crystal structure information or quantum mechanical calculations. We focus specifically on a class of organic compounds categorized as energetic materials called high explosives (HE) and predicting their crystalline density. An ongoing challenge within the chemistry machine learning community is deciding how best to featurize molecules as inputs into machine learning models-whether expert handcrafted features or learned molecular representations via graph-based neural network models-yield better results and why. We evaluate both types of representations in combination with a number of machine learning models to predict the crystalline densities of HE-like molecules curated from the Cambridge Structural Database, and we report the performance and pros and cons of our methods. Our message passing neural network (MPNN) based models with learned molecular representations generally perform best, outperforming current state-of-the-art methods at predicting crystalline density and performing well even when testing on a data set not representative of the training data. However, these models are traditionally considered black boxes and less easily interpretable. To address this common challenge, we also provide a comparison analysis between our MPNN-based model and models with fixed feature representations that provides insights as to what features are learned by the MPNN to accurately predict density.

Metabolic health measurements of shift workers in a national cross-sectional study: Results from the Canadian Health Measures Survey.

BACKGROUND: Shift work exposure may be a concern for a range of health effects, including metabolic health outcomes such as insulin resistance, high body weight, and abdominal obesity. METHODS: We analyzed shift work and indicators of metabolic health (overweight/obesity defined by body mass index, self-reported changes in body mass index (BMI) in previous 1 and 10 years, waist circumference, waist-to-hip ratio, and insulin resistance assessed by the homeostasis model assessment 2 (HOMA-2-IR)) in the cross-sectional Canadian Health Measures Survey (CHMS). We analyzed descriptive characteristics of shift workers (regular night, evening, and rotating shift) and used multivariable linear regression to examine the association between two definitions of shift work exposure and measures of metabolic health, adjusted for age, sex, daily energy expenditure, sleep, and poor dietary quality. RESULTS: 5470 anthropometry (2637 fasting) participants in CHMS Cycles 1 and 2 were included, of whom 16.5% worked regular evening, night, or rotating shifts. Shift workers were younger and slept longer hours than non-shift workers. Bivariate associations showed inverse relationships between shift work and BMI, waist circumference, waist-to-hip ratio, and HOMA-2-IR. In adjusted analyses, BMI was inversely related to shift work, and other metabolic health outcomes showed no significant associations. CONCLUSIONS: Healthy worker effects (including self-selection of exposure) could explain inverse relationships, particularly as the cross-sectional design only allowed assessment of current exposure. Key strengths include the population-based design and measurement of metabolic health indicators. Results underscore the importance of consideration of the health of shift workers following departure from the exposed population.

Effects of MTHFR C677T polymorphism on vitamin D, homocysteine and natural killer cell cytotoxicity in women with recurrent pregnancy losses.

STUDY QUESTION: Is there any relationship between vitamin D [25 (OH) vitamin D], total plasma homocysteine and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in women with recurrent pregnancy losses (RPL)? SUMMARY ANSWER: Women with MTHFR 677TT (homozygous mutation, TT) genotype have significantly lower vitamin D levels, higher homocysteine and natural killer (NK) cell cytotoxicities than those of women with MTHFR 677CC (wild type, CC) and 677CT (heterozygous mutation, CT) genotypes. WHAT IS KNOWN ALREADY: Vitamin D insufficiency, MTHFR C677T polymorphism and hyperhomocysteinemia have been reported as risk factors for RPL. However, the relationship between these risk factors is not known in this population. STUDY DESIGN, SIZE, DURATION: This is a retrospective cross-sectional study, including 837 women with RPL, who were enrolled in Reproductive Medicine and Immunology, Chicago Medical School, between 2012 and 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with two or more RPL prior to 20 weeks of gestation were included. To investigate whether the MTHFR C677T polymorphism affects the levels of homocysteine and vitamin D as well as immune parameters in women with RPL, biochemical data, such as plasma total homocysteine and serum vitamin D levels, and immune parameters, including NK cell cytotoxicity, were analyzed by MTHFR C677T genotype (CC, CT and TT). MAIN RESULTS AND THE ROLE OF CHANCE: The serum level of vitamin D in TT was significantly lower when compared with those of CT (P = 0.001) and CC (P = 0.003), while the level of homocysteine in TT was significantly higher than those in CT (P = 0.01) and CC (P = 0.01). NK cytotoxicity in TT was significantly higher than that of CC (P = 0.04) but not CT (P = 0.09). There was a significant negative correlation between the levels of vitamin D and homocysteine in TT (r = -0.357, P < 0.01). In multivariate analysis, vitamin D insufficiency (<30 ng/ml) was an independent risk factor for hyperhomocysteinemia (adjusted odds ratio 1.89, 95% CI 1.41-2.52). LIMITATIONS, REASONS FOR CAUTION: The study was retrospective and included only women with RPL but not healthy fertile controls. In addition, folic acid, vitamin B6 and B12 intake, which could modify the level of homocysteine and vitamin D, were not investigated. Thus, a considerable part of women might have folic acid and vitamin D supplementation and prenatal vitamin pills, and there are probable confounders in this study associated with unrestricted vitamin supplementation. Therefore, the findings should be carefully interpreted and applied to RPL women with MTHFR gene polymorphism. WIDER IMPLICATIONS OF THE FINDINGS: The findings attained in this analysis regarding the MTHFR polymorphism and its relationship with vitamin D, homocysteine and NK cytotoxicity may aid in uncovering the underlying etiology and mechanism for RPL. The study highlights an interplay between nutrition and immune responses in RPL. STUDY FUNDING/COMPETING INTEREST(S): No external funding was received for this study. None of the authors have any conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Iodide Transporters in the Endometrium: A Potential Diagnostic Marker for Women with Recurrent Pregnancy Failures.

OBJECTIVE: The element iodine is an essential nutrient utilized by the thyroid glands, and deficiency of this element has been linked to reproductive failures. Iodide transporters are also present in reproductive tissues and cells of embryonic origin such as the endometrium and trophoblasts, respectively. The aim of this study is to understand if levels of iodide transporters are linked to pregnancy outcomes. SUBJECTS AND METHODS: RNA derived from endometrial biopsies from controls or women with recurrent reproductive failures was analyzed utilizing RT-PCR and targeted RNASeq. RESULTS: When compared to controls, women with 2 or more reproductive failures had a significant increase (>5 fold) in mRNA levels of the iodine transporters NIS and PENDRIN, but not thyroglobulin when probed vis RT-PCR. Targeted RNASeq analysis confirmed these findings when another group of patients were analyzed. CONCLUSION: These findings suggest possible abnormal iodine metabolism and a deficiency of iodine in endometrial tissues from some of the women with reproductive failures. We hypothesize from these findings that inorganic iodide and/or iodine is required for optimal cellular function in reproductive tissues, and that iodide transporters may potentially be used as a marker for infertility or for probing potential localized iodine deficiency that may not present in a typical thyroid panel analysis.

Endometrial TGF-ß, IL-10, IL-17 and autophagy are dysregulated in women with recurrent implantation failure with chronic endometritis.

BACKGROUND: Chronic endometritis (CE) is a condition which results in reduced receptivity of embryos by dysregulated lymphocyte subsets, abnormal expression of cytokines, chemokines and other regulatory molecules in the endometrium (EM). Macroautophagy (autophagy), the highly conserved cellular homeostasis pathway, plays an essential role in the development and function of T lymphocytes, and supports T cell lineage stability and survival fitness. The possible relationships between autophagy and local cytokine milieus in repeated implantation failure (RIF) with CE have not been elucidated yet. METHODS: This case-control study was performed at a large reproductive medicine center between February 2015 and July 2016. Seventy-five recurrent implantation falliure women with CE who had "strawberry aspect" and 75 women with male factor infertility were included. In this study, endometrial expressions of IL-17, IL-10, TGF-ß and autophagy related molecules, including LC3-II and mTORC1 were investigated by qRT-PCR, Western blot, immunofluorescence and immunohistochemistry assays. RESULTS: The expression of IL-17 was significantly higher in patients with CE compared to women with male factor infertility, while the expressions of IL-10 and TGF-ß were significantly lower. Moreover, the expression of autophagy (LC3-II) is increased, while the expression of mTORC1 was impaired. CONCLUSIONS: CE is associated with shifted cytokine milieu towards Th17 over Treg immunity in endometrium through impaired autophagy by decreased mTORC1.

The current burden of cancer attributable to occupational exposures in Canada.

Exposure to occupational carcinogens is often overlooked as a contributor to the burden of cancer. To estimate the proportion of cancer cases attributable to occupational exposure in Canada in 2011, exposure prevalence and levels of 44 carcinogens were informed by data from the Canadian carcinogen exposure surveillance project (CAREX Canada). These were used with Canadian Census (between 1961 and 2011) and Labour Force Survey (annual surveys between 1976 and 2013) data to estimate the number of workers ever exposed to occupational carcinogens. Risk estimates of the association between each carcinogen and cancer site were selected mainly from published literature reviews. Population attributable risks were estimated using Levin's equation and applied to the 2011 cancer statistics from the Canadian Cancer Registry. It is estimated that 15.5 million Canadians alive in 2011 were exposed, during at least one year between 1961 and 2001, to at least one carcinogen in the workplace. Overall, we estimated that in 2011, between 3.9% (95% CI: 3.1%-8.1%) and 4.2% (95% CI: 3.3%-8.7%) of all incident cases of cancer were due to occupational exposure, corresponding to lower and upper numbers of 7700-21,800 cases. Five of the cancer sites - mesothelioma, non-melanoma skin cancer, lung, female breast, and urinary bladder - account for a total of 7600 to 21,200 cancers attributable to occupational exposures such as solar radiation, asbestos, diesel engine exhaust, crystalline silica, and night shift work. Our study highlights cancer sites and occupational exposures that need recognition and efforts by all stakeholders to avoid preventable cancers in the future.

The impact of night shift work on breast cancer: Results from the Burden of Occupational Cancer in Canada Study.

BACKGROUND: We estimated the proportion and number of female breast cancer cases in Canada attributable to night shift work, a probable cause of breast cancer. METHODS: Levin's equation was used to calculate population attributable fractions (PAFs) among Canadian women who ever worked night/rotating shifts from 1961 to 2000, accounting for labor turnover and survival to the year 2011. The calculated PAFs were applied to 2011 Canadian breast cancer incidence statistics to obtain the number of attributable cases. RESULTS: Approximately 1.5 million women ever worked night/rotating shifts during 1961-2000 and survived to 2011. The PAFs ranged from 2.0% (95% confidence interval [CI]: 1.4-6.2) to 5.2% (95% CI: 3.7-13.6), and 470 to 1200 incident breast cancer cases in 2011 were likely due to shift work, of which 38% would have been diagnosed among women in health-related occupations. CONCLUSIONS: More research is needed to increase the certainty of this association, but current evidence supports workplace-based prevention.

Burden of lung cancer attributable to occupational diesel engine exhaust exposure in Canada.

OBJECTIVE: To estimate the population attributable fraction (PAF) and number of incident and fatal lung cancers in Canada from occupational exposure to diesel engine exhaust (DEE). METHODS: DEE exposure prevalence and level estimates were used with Canadian Census and Labour Force Survey data to model the exposed population across the risk exposure period (REP, 1961-2001). Relative risks of lung cancer were calculated based on a meta-regression selected from the literature. PAFs were calculated using Levin's equation and applied to the 2011 lung cancer statistics obtained from the Canadian Cancer Registry. RESULTS: We estimated that 2.4% (95% CI 1.6% to 6.6%) of lung cancers in Canada are attributable to occupational DEE exposure, corresponding to approximately 560 (95% CI 380 to 1570) incident and 460 (95% CI 310 to 1270) fatal lung cancers in 2011. Overall, 1.6 million individuals alive in 2011 were occupationally exposed to DEE during the REP, 97% of whom were male. Occupations with the highest burden were underground miners, truck drivers and mechanics. Half of the attributable lung cancers occurred among workers with low exposure. CONCLUSIONS: This is the first study to quantify the burden of lung cancer attributable to occupational DEE exposure in Canada. Our results underscore a large potential for prevention, and a large public health impact from occupational exposure to low levels of DEE.

Pregnancy complicated with PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) syndrome: a case report.

BACKGROUND: Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome has been considered as a childhood syndrome. The underlying etiology of PFAPA syndrome is unclear however, currently considered as auto-immune inflammatory disease. Recently, a few cases of adult-onset of PFAPA syndrome have been reported. However, there is no report about the successful management of pregnancy complicated with PFAPA syndrome. CASE PRESENTATION: The patient was a 31-year-old woman who developed recurrent episodes of high fever associated with cervical adenitis, pharyngitis and vomiting started 9 months after a delivery. She was diagnosed with PFAPA syndrome and cimetidine 800 mg/day was initiated. Since then, these symptoms got better. Cimetidine treatment was discontinued since she became pregnant (6 weeks of pregnancy). Except one febrile episode at 8 weeks gestation, she did not develop a febrile episode during pregnancy. Peripheral blood Th1/Th2 ratio was decreased from the first trimester to the second trimester of pregnancy. Then again, the ratio was steadily elevated during the third trimester. At 38 weeks, she delivered a live born infant without any complication. Two months after delivery, she developed PFAPA syndrome again and cimetidine treatment was re-initiated. However, febrile episodes were not controlled well, and Th1/Th2 ratio was further elevated compared to pregnancy status. Colchicine 0.5 mg once a day was initiated. Symptoms were diminished and Th1/Th2 ratio was gradually decreased. CONCLUSION: There was no case report of pregnancy complicated with PFAPA syndrome, though there were several reports of adult-onset PFAPA cases without pregnancy. The current case may be the first case report of a successful pregnancy complicated with PFAPA. In this case, PFAPA symptoms were ameliorated during pregnancy, but reappeared after delivery. We speculate that PFAPA syndrome, a Th1 type immune disorder, might be improved due to the Th1 to Th2 shifting, which was induced by pregnancy. It is necessary to investigate further about PFAPA syndrome with pregnancy and Th1/Th2 immune responses in the future.

The economic burden of occupational non-melanoma skin cancer due to solar radiation.

Solar ultraviolet (UV) radiation is the second most prevalent carcinogenic exposure in Canada and is similarly important in other countries with large Caucasian populations. The objective of this article was to estimate the economic burden associated with newly diagnosed non-melanoma skin cancers (NMSCs) attributable to occupational solar radiation exposure. Key cost categories considered were direct costs (healthcare costs, out-of-pocket costs (OOPCs), and informal caregiver costs); indirect costs (productivity/output costs and home production costs); and intangible costs (monetary value of the loss of health-related quality of life (HRQoL)). To generate the burden estimates, we used secondary data from multiple sources applied to computational methods developed from an extensive review of the literature. An estimated 2,846 (5.3%) of the 53,696 newly diagnosed cases of basal cell carcinoma (BCC) and 1,710 (9.2%) of the 18,549 newly diagnosed cases of squamous cell carcinoma (SCC) in 2011 in Canada were attributable to occupational solar radiation exposure. The combined total for direct and indirect costs of occupational NMSC cases is $28.9 million ($15.9 million for BCC and $13.0 million for SCC), and for intangible costs is $5.7 million ($0.6 million for BCC and $5.1 million for SCC). On a per-case basis, the total costs are $5,670 for BCC and $10,555 for SCC. The higher per-case cost for SCC is largely a result of a lower survival rate, and hence higher indirect and intangible costs. Our estimates can be used to raise awareness of occupational solar UV exposure as an important causal factor in NMSCs and can highlight the importance of occupational BCC and SCC among other occupational cancers.