Evaluation of lead body burden in US adolescents.

The objective was to examine key determinants in the body burden of lead in adolescents as lead poisoning remains a major public health challenge. Data from 2,925 teenagers aged 12-18 older in the National Health and Nutrition Examination Survey (NHANES), 1999-2012 were analyzed. Lead in both blood and urine was significantly correlated among individuals. Despite higher blood lead in males, urinary lead measures corrected for dilution were similar between male and female adolescents. Thus, the urine-to-blood ratio was approximately 30% lower in male than female adolescents, suggesting that differences in renal disposal contributed to the greater body burden for young males. Differences in urinary lead disposal appear to be a key determinant in lead accumulation and thus, the degree of lead poisoning. Direct renal studies should be conducted to determine mechanisms and potential solutions.

A case-control study of occupational risk factors for pancreatic cancer in poultry plant workers: a random forest approach.

BACKGROUND: Poultry plant workers are exposed to chemical carcinogens and oncogenic viruses in their work environment. Our objective was to identify jobs and workplaces related to poultries that could increase the pancreatic cancer risk. METHODS: We conducted a case-control study within a defined cohort of poultry workers. We used a random forest algorithm to identify features that could increase pancreatic cancer in the poultry plant workers. RESULTS: The mean age of participants was 59.49 years. The majority of the study participants were females (51.30%) and Whites (71.0%). The following workplaces and job tasks had an association with increased pancreatic cancer mortality: working in chicken and turkey plants, working in plants where food products were processed and canned, working in a place where poultry and animals where present, working as a hunter for game animals, working as a veterinarian in places had animals and different poultry birds, working in pet houses and working in places where birds were handled and killed. The accuracy and the area under the curve of the model were 72.3 and 71.50%. CONCLUSION: Chicken and turkey plant workers could be at risk for pancreatic cancer mortality. We need to confirm the results in future studies.

Management of optic disc pit maculopathy: the European VitreoRetinal society optic pit study.

PURPOSE: To evaluate a variety of techniques, and their anatomical and functional results, for the treatment of optic disc pit maculopathy (ODP-M). A secondary aim was to report on results of secondary procedures in cases of initial failure or recurrence. METHODS: Multicentre retrospective study of 95 eyes with ODP-M, treated by 25 surgeons from 12 countries. Primary outcomes were anatomical resolution of subretinal fluid (SRF), intraretinal fluid (IRF) and visual acuity (VA) at 12 months. RESULTS: Higher rates of SRF and IRF resorption were achieved in eyes treated with pars plana vitrectomy (PPV) compared to external laser with or without tamponade: 64/72 (88.9%) versus 8/14 (57.1%) for SRF (p = 0.003), and 50/59 (84.7%) versus 3/10 (30%) for IRF (p = 0.002). The addition of juxtapapillary laser or internal limiting membrane (ILM) peel during PPV did not improve SRF or IRF resolution. Pars plana vitrectomy (PPV) with tamponade and PPV with tamponade plus endolaser were associated with significant visual gain. In the former group, VA improved from a mean of logMAR 0.91 (20/162), to a mean of logMAR 0.52 (20/66) at 12 months; in the latter group, VA improved from a mean of logMAR 0.82 (20/132) to a mean of logMAR 0.47 (20/59) at 12 months. Retreatments were performed in 14 eyes (15.7%), only enhancing anatomical outcomes. CONCLUSION: Vitrectomy with tamponade had better final outcomes than external laser treatment with or without gas tamponade. Laser endophotocoagulation and ILM peel provided no additional benefit. A secondary treatment resulted in anatomical but not functional improvement.

The Relationship between Insulin Resistance and Spatial QRS-T Angle in American Adults.

BACKGROUND: Insulin resistance can impair the electrical conductivity of the heart. Spatial QRS-T axis reflects ventricular depolarization and repolarization. The relationship between insulin resistance and spatial QRS-T angle has not been examined in the general population. OBJECTIVE: We examined the relationship between insulin resistance and spatial QRS-T angle in an American population-based sample. METHODS: We used data collected from the National Health and Nutrition Examination Survey III (NHANES III), and a directed acyclic graph to select confounders. We fitted logistic regression models and adjusted for the effect of the confounders. We stratified all analyses by gender. RESULTS: The odds ratios (OR) of the abnormal QRS-T angle and their 95% confidence intervals (CI) for females and males were 1.08 (1.03-1.16) and 1.03 (0.96-1.11), respectively. A 5-unit increase in insulin resistance in females increased the odds of an abnormal QRS-T angle by 47% (OR = 1.47, 95% CI, 1.10-2.10); in males, a 5-unit increase in insulin resistance increased the OR by 17% (OR = 1.17, 95% CI, 0.82-1.70). CONCLUSIONS: Spatial QRS-T angle may be associated with insulin resistance, especially in women. The individuals with a higher insulin resistance value had higher odds for major adverse cardiovascular events. Nevertheless, the results of this study should be verified in prospective studies.

Intraoperative Complications and Visual Outcomes of Cataract Surgery in Diabetes Mellitus: A Multicenter Database Study.

PURPOSE: To compare the visual outcome and the rate of intraoperative complications in eyes of diabetic and nondiabetic patients undergoing phacoemulsification over 15 years. DESIGN: Retrospective clinical cohort study. METHODS: Data of 179,159 eyes that underwent phacoemulsification at 8 centers were classified based on the presence or absence of diabetes mellitus. Visual acuity (VA) was defined as the best value of uncorrected or corrected distance measure available. For the VA analysis, eyes with co-pathologies or combined surgical procedures were further excluded, leaving a subset of 90,729 eyes. Main outcome measures were logarithm of the minimum angle of resolution (logMAR) VA at 4-12 weeks postoperatively, and rate of intraoperative complications. RESULTS: Cataract surgery in eyes of diabetic patients was associated with an improvement in mean VA of 0.48 logMAR (5 Snellen lines). Mean postoperative VA was slightly worse in diabetic compared to nondiabetic group (logMAR 0.23 vs 0.13; Snellen 20/30 vs 20/25; P < .0001) and the proportions of eyes achieving a visual gain of ≥3 Snellen lines (≥0.3 logMAR) was lower in the diabetic group (56.6% vs 63.5%; P < .0001). There was a linear relationship between diabetic retinopathy severity and worse postoperative visual acuity (ß coefficient 0.098 to 0.288; P < .0001). We observed higher rates of posterior capsule rupture (2.3% vs 1.6%; P < .001) and dropped nuclear fragments (0.3% vs 0.2%; P < .001) in the diabetic group. CONCLUSIONS: Postoperative VA negatively correlated with diabetes and diabetic retinopathy severity. Eyes of diabetic subjects had higher risks of posterior capsule rupture.

The difference between hypertension determined by self-report versus examination in the adult population of the USA: Continuous NHANES 1999-2016.

BACKGROUND: Studies have considered the validity of self-reported hypertension relative to hypertension detected by examination; no study has explored trends in the difference between these two measures. Our objective was to calculate these differences overtime within subpopulations of the USA. METHODS: We included non-Hispanic white, non-Hispanic black and Hispanic adults who participated in the National Health and Nutrition Examination Surveys from 1999 to 2016, in the analysis (N = 44 333). We subtracted self-reported hypertension from hypertension detected by examination to calculate blood pressure difference (BPD). We fit weighted linear regression models that included important covariates along with all combination of two- and three-way interactions to predict the BPD. We used the fitted lines of the models to depict the patterns of differences in the different subpopulations. RESULTS: Age ≥ 45 years, lack of annual clinical visit, body mass index (BMI) < 25 and time were important factors associated with increased BPD. CONCLUSIONS: People who are ≥ 45 years, have normal BMI, or do not have annual medical visits are more likely to have a bigger BPD. We can use the calculated BPD, to adjust estimates of the prevalence of self-reported hypertension.

Training cosmetology students in Arkansas to help dermatologists find skin cancers earlier: results of a cluster-randomized controlled trial.

BACKGROUND: We tested an educational video in cosmetology schools to increase students' knowledge about skin cancer, sun-safety practices, identifying suspicious lesions and recommending clients consult a dermatologist when a suspicious lesion is observed. METHODS: We used a cluster-randomized controlled study design to randomize 22 cosmetology schools to receive our educational video or a publicly accessible healthy lifestyle video (control). RESULTS: Students who received the intervention were more likely than controls to increase their knowledge of skin cancer, risk factors and how to identify potential skin cancers (risk ratio [RR] and 95% confidence interval = 2.86 [1.58-5.20]). At follow-up, students in the intervention group were more likely than those in the control group to look for suspicious moles on their clients' faces, scalps and necks (RRs = 1.75, 2.16 and 2.90, respectively). Additionally, students in the intervention group were more likely to communicate with clients about sun-safety practices (RR = 1.74 [1.11-2.73]) and consulting a dermatologist about suspicious moles (RR = 1.57 [1.03-2.41]). CONCLUSIONS: Our educational video helped cosmetology students recognize potential skin cancers and talk with clients about sun safety and consulting a dermatologist about suspicious moles. Such videos may play a role in the public health surveillance of skin cancers in communities.

Race, Nativity, and Sex Disparities in Human Papillomavirus Vaccination Among Young Adults in the USA.

Research has demonstrated that the human papillomavirus (HPV) vaccine is a safe and effective way to decrease HPV-related cervical cancers; however, the vaccination rate in the USA is suboptimal. The current study examined racial and ethnic disparities in HPV vaccination among a nationally representative sample, including Native Hawaiian and Pacific Islanders (NHPI). This study also investigated the associations between nativity and vaccination, and sex differences between race/ethnicity and vaccination and nativity and vaccination. A cross-sectional study was conducted with a sample of adults aged 18-26 years drawn from the 2014 NHPI National Health Interview Survey (n = 2590) and the general 2014 National Health Interview Survey (n = 36,697). Log-binomial models were fitted to examine differences in vaccination. There was a statistically significant racial/ethnic difference in HPV vaccination (p = 0.003). More women than men were vaccinated (41.8% vs. 10.1%) (p < 0.001). There was a significant difference in HPV vaccination based on nativity: 27.4% of adults aged 18 to 26 years who were born in the USA and 27.7% born in a US territory received the HPV vaccine compared with 14.3% among those not born in the USA or a US territory (p < 0.001). The association of HPV vaccination with nativity and race/ethnicity differed by sex and showed several nuanced differences. Overall, the prevalence of HPV vaccination was low. The study's findings demonstrate the need for public health strategies to increase vaccination rates among all populations, with the critical need to identify strategies that are effective for men, racial/ethnic minorities, and immigrant women born outside the USA.

Metabolic syndrome and P-wave duration in the American population.

PURPOSE: Metabolic syndrome has a high prevalence in the United States. P-wave duration is a valuable indicator for atrial electrical conduction. Abnormalities in atrial electrical conduction can predispose to atrial fibrillation. Our objective was to estimate the effect of metabolic syndrome on P-wave duration in a nationally representative sample. METHODS: We included 6499 adults who participated in the National Health and Nutrition Examination Survey III (1988-1994). We estimated the effect of metabolic syndrome and its components on P-wave duration after adjusting for confounders such as demographic and lifestyle variables. We stratified the analyses by gender. RESULTS: Irrespective of gender, participants with metabolic syndrome had a longer P-wave duration than that of those without it. In addition, we observed a positive linear dose-response relation between metabolic syndrome components and P-wave duration. CONCLUSIONS: Patients with metabolic syndrome had a longer P-wave duration. They might have been at a higher risk for atrial fibrillation and mortality; they need to be periodically checked by their health care providers. However, the results of this study should be confirmed in prospective studies.

Consumption of Vitamin K and Vitamin A Are Associated With Reduced Risk of Developing Emphysema: NHANES 2007-2016.

Chronic obstructive pulmonary disease (COPD) comprising of emphysema and chronic bronchitis are the most common chronic respiratory diseases that impart a huge economic and clinical burden. Factors other than smoking and air pollutants can cause inflammation and emphysematous changes in the lung airspaces or alveoli have been understudied. Using a cross-sectional study design, we assessed the association of dark green vegetables, vitamin K and Vitamin A with emphysema status among adults at U.S. These nutrients have a role in lung biology. A complete case NHANES data (n = 17,681) was used. After adjusting for modifiable and non-modifiable confounders, consumption of recommended amounts of vitamin K was associated with 39% decrease in odds (Odds Ratio: 0.61; 95% CI: 0.40-0.92, P-val: 0.02) of emphysema. Similarly consumption of recommended amounts vitamin A dose was associated with 33% decrease in odds (Odds Ratio: 0.67; 95% CI: 0.44-1.00, P-val: 0.05) of emphysema. Vitamin K shows an inverse association suggesting that it may be important in slowing the emphysematous process. Vitamin A is important in maintaining the anti-inflammatory process. Together vitamin K and vitamin A are important in the lung health.

The association of metabolic syndrome and QRS|T angle in US adults (NHANES III).

BACKGROUND: Spatial QRS|T angle is a predictor of cardiovascular events. Those with metabolic syndrome have an increased risk of cardiovascular morbidity and mortality. This study investigated the association between metabolic syndrome and spatial QRS|T angle. METHODS: We obtained data from the National Health and Nutritional Examination Survey III on 6,249 adults. We calculated spatial QRS|T angle from the standard 12-lead electrocardiogram and classified it as abnormal, borderline, or normal. We identified metabolic syndrome if at least three of the following were present: abdominal obesity, elevated blood pressure, elevated triglycerides, decreased high-density lipoprotein (HDL), and impaired fasting glucose. We used weighted logistic regression to estimate the effect of metabolic syndrome and its components on QRS|T angle while stratifying by gender and adjusting for age, race, smoking status, heart rate, PR, QT, and QRS interval, and QRS amplitude. RESULTS: Among men and women, metabolic syndrome, the number of components present, elevated blood pressure, and impaired fasting glucose were positively associated with QRS|T angle. Among women, decreased HDL and abdominal obesity were also positively associated with QRS|T angle. CONCLUSIONS: This study suggests that persons with metabolic syndrome may be at increased risk for ventricular arrhythmias. The use of spatial QRS|T angle to assess this cardiovascular risk is warranted.

The Influence of Diabetes Status on the Rate of Cataract Surgery Following Pars Plana Vitrectomy.

PURPOSE: We aimed to evaluate the association between diabetic status and the rates of cataract extraction (CE) following pars plana vitrectomy (PPV). DESIGN: Retrospective cohort, multicenter database study. PARTICIPANTS: Patients were selected from an insurance claims database (PharMetrics LifeLink) that included persons who had filed claims between 2006 and 2015 in the United States. METHODS: We analyzed the records of 22 146 patients who underwent PPV performed by 2705 retina physicians. The vitrectomy group included patients ≥18 years of age who had undergone PPV. The control group included patients who were matched to the vitrectomy group 1:2 based on sex, diabetes mellitus (DM) status, region of the United States, and Charleston Comorbidity Index. MAIN OUTCOME MEASURES: Hazard ratios (HRs) and rates of cataract surgery in patients with and without diabetes who had undergone prior PPV. RESULTS: The hazard ratio for post-PPV CE was lower among patients with diabetes (3.307; 95% confidence interval [CI], 3.051-3.583) than among patients without diabetes (4.889; 95% CI, 4.670-5.119). This association was significant for all subgroups of patients with diabetes except in patients with diabetes and without retinopathy (4.086; 95% CI, 3.511-4.754). There was a significantly longer time between PPV and CE in patients with diabetes (537 days; 95% CI, 459-677 days) compared with those without diabetes (295 days; 95% CI, 278-312 days). The type of DM (type 1 vs. type 2) did not influence the rate of post-PPV cataract surgery. In persons with diabetes who underwent PPV, we observed a trend for a lower HR of cataract surgery in eyes with proliferative retinopathy (0.903; 95% CI, 0.725-1.124), and nonproliferative retinopathy (0.965; 95% CI, 0.721-1.290) compared with eyes with no retinopathy. CONCLUSIONS: Eyes of patients with diabetes had a significantly decreased risk of undergoing CE after PPV surgery compared with eyes of patients without diabetes.

Using Machine Learning to Predict Progression in the Gastric Precancerous Process in a Population from a Developing Country Who Underwent a Gastroscopy for Dyspeptic Symptoms.

BACKGROUND: Gastric cancer is the fourth most common cancer and the third most common cause of cancer deaths worldwide. Morbidity and mortality from gastric cancer may be decreased by identification of those that are at high risk for progression in the gastric precancerous process so that they can be monitored over time for early detection and implementation of preventive strategies. METHOD: Using machine learning, we developed prediction models for gastric precancerous progression in a population from a developing country with a high rate of gastric cancer who underwent gastroscopies for dyspeptic symptoms. In the data imputed for completeness, we divided the data into a training and a validation test set. Using the training set, we used the random forest method to rank potential predictors based on their predictive importance. Using predictors identified by the random forest method, we conducted best subset linear regressions with the leave-one-out cross-validation approach to select predictors for overall progression and progression to dysplasia or cancer. We validated the models in the test set using leave-one-out cross-validation. RESULTS: We observed for all models that complete intestinal metaplasia and incomplete intestinal metaplasia were the strongest predictors for further progression in the precancerous process. We also observed that a diagnosis of no gastritis, superficial gastritis, or antral diffuse gastritis at baseline was a predictor of no progression in the gastric precancerous process. The sensitivities and specificities were 86% and 79% for the general model and 100% and 82% for the location-specific model, respectively. CONCLUSION: We developed prediction models to identify gastroscopy patients that are more likely to progress in the gastric precancerous process, among whom routine follow-up gastroscopies can be targeted to prevent gastric cancer. Future external validation is needed.

Corrigendum to "Oral Health Knowledge and Behavior among Adults in the United Arab Emirates".

[This corrects the article DOI: 10.1155/2019/7568679.].

A Case-Cohort Study to Investigate the Excess of Liver Cancer Observed in Workers in Poultry Slaughtering & Processing Plants.

This is a case-cohort study to examine whether the excess of liver cancer deaths observed in workers in poultry plants could be explained by oncogenic viruses and chemical carcinogenic exposures within the plants. A detailed telephone questionnaire was administered, and responses were analyzed by logistic regression. Odds ratios for several indicators of high exposure to oncogenic viruses or chemical carcinogens in poultry plants and related industries were elevated, but not statistically significant, except the odds ratio for direct contact with the blood of meat in kitchens, eating places, etc. Established risk factors were replicated, and new ones identified. The study was unable to unequivocally assess risks due to oncogenic viruses or chemical carcinogenic exposures in poultry plants, mainly because observed elevated risks did not achieve statistical significance. The same also applies to some non-occupational factors. Noteworthy risk factors identified include the increased risks for eating cabbage, mussels, blood sausage, meringue, playing football, and decreased risks for history of frequent intake of soft drinks, gelatin-based meals, vitamins, frequent use of microwave oven to cook, and history of childhood diseases, and nonspecific symptoms. The significance of these findings is unknown, and they will need to be replicated in studies with adequate statistical power.

The Association between Salt and Potential Mediators of the Gastric Precancerous Process.

BACKGROUND: The process by which salt affects the gastric precancerous process has not been adequately studied in humans. METHODS: We investigated the effects of salt on gastric inflammation, epithelial damage, the density of Helicobacter pylori infection, and gastric epithelial cell proliferation, all of which may be mediators between salt and gastric precancerous/cancerous lesions. These potential mediators were measured using gastric biopsies as: (a) the density of polymorphonuclear and mononuclear cells (gastric inflammation), (b) mucus depletion (gastric epithelial damage), and (c) the severity of H. pylori infection. Salt intake was measured with spot urine samples (using urinary sodium/creatinine ratios), self-reported frequency of adding salt to food, and as total added salt. RESULTS: The average sodium/creatinine ratio (at baseline and post-treatment at five months) was associated with increased epithelial damage over the 12-year follow-up period among those with a greater severity of chronic inflammation and among those with continued H. pylori infection after treatment at five months. This association was stronger when both severe gastric inflammation and H. pylori infection were present at five months (ß: 1.112, 95% CI: 0.377, 1.848). CONCLUSION: In humans, salt was associated with an increase in epithelial damage in stomachs with more severe previous H. pylori-induced chronic inflammation.

Association between Dietary Salt Intake and Progression in the Gastric Precancerous Process.

Gastric cancer is the third leading cause of cancer mortality worldwide. Studies investigating the effect of salt on gastric cancer have mainly used self-reported measures, which are not as accurate as sodium/creatinine ratios because individuals may not know the amount of salt in their food. Using data from a prospective cohort study, we investigated the effect of salt intake on progression to gastric precancerous lesions. Salt intake was estimated by urinary sodium/creatinine ratios, self-reported frequencies of adding salt to food, and total added table salt. We repeated the analyses among groups with and without Helicobacter pylori infection. We did not observe a positive association between salt intake, measured by urinary sodium/creatinine ratio, and overall progression in the gastric precancerous process (adjusted risk ratio (RR): 0.94; 95% confidence interval (CI) 0.76-1.15). We did observe an association between salt intake and increased risk for progression to dysplasia or gastric cancer overall (adjusted risk ratio (RR): 1.32; 95% confidence interval (CI): 0.96-1.81), especially among those who continued to have H. pylori infection at the five-month follow-up (adjusted RR: 1.53; 95% CI: 1.12-2.09), and among those who had persistent H. pylori infection over 12 years (adjusted RR: 1.49; 95% CI: 1.09-2.05). Salt intake may increase the risk of gastric dysplasia or gastric cancer in individuals with H. pylori infection.

Oral Health Knowledge and Behavior among Adults in the United Arab Emirates.

Background: The prevalence of periodontal diseases is increasing in the United Arab Emirates (UAE) despite a worldwide decline in the prevalence of dental caries among children and adolescents. The aims of this study were to determine the levels of oral health knowledge and health-related behavior in adult UAE residents, and the relationship between these variables and oral health. Methods: A descriptive cross-sectional survey with nonprobability sampling was used in this study. A sample of 630 adults residing in the UAE completed an oral health survey to assess their oral health knowledge and behavior. Mean oral health knowledge and behavior scores were calculated and correlated with population demographic and behavioral variables. Results: Participants were found to have an acceptable oral health knowledge score (OHKS) of 10.50 (2.36) where 62 % of participants answered the questions correctly. Results showed that age, gender, nationality, smoking, and physical activity were significantly associated with the knowledge score. However, only gender, nationality, and smoking predicted oral health knowledge scores after further regression analysis. On the other hand, the mean oral health behavior score (OHBS) for all participants was 8.91 (2.29); 98% of all participants practiced at least an acceptable level of oral behavior and 53% practiced a good to perfect level. Age, gender, educational level, employment status, insurance status, marital status, nationality, smoking, and physical activity showed significant statistical association with the score of behaviors related to oral health. Only gender, number of diabetes sessions attended, and health information sources used remained significant after further regression analysis. Conclusion: Further efforts are required to spread awareness about oral health and encourage the UAE population to develop healthy oral habits. Such programs will decrease the occurrence and burden of many chronic oral diseases especially periodontal diseases.

The relation of blood lead and QRS-T angle in American adults.

The QRS-T angle is a key ECG predictor for ventricular arrhythmia. Lead has a strong relation with cardiovascular diseases; however, no study has been conducted to investigate the association between lead exposure and QRS-T angle. Thus, we explored this association in a population-based representative sample: NHANES III. We used the standard 12-lead ECGs to calculate Spatial QRS-T angles. Blood lead concentration was measured using graphite furnace atomic absorption spectrophotometry method. We conducted multivariate weighted logistic regression to adjust for impaired fasting glucose, hypertension, poverty index, age, race, and smoking status. We found that when the log of blood lead increased by one unit, the odds of an abnormal QRS-T angle increased by 34% among men and 4% among women. We suggest the use of QRS-T angle deviation among those who are exposed to lead to detect individuals at risk for adverse cardiovascular outcomes such as arrhythmias.

Excess lung cancer occurrence in poultry plants. Occupational risk factors: Findings for oncogenic viruses exposure and other occupational exposures.

Certain viruses naturally infect and cause cancer in chickens and turkeys. Humans are widely exposed. The viruses cause cancer in primates, and transform human cells in vitro, but it is not known if they cause cancer in humans, mainly because of the lack of epidemiologic evidence. We conducted cohort mortality studies of workers in poultry slaughtering/processing plants across the United States, because they have the highest human exposures. An excess of lung cancer and other deaths was recorded in the poultry workers. Here, we report on a case-cohort study of the lung cancer deaths nested within these cohorts, that was conducted to provide epidemiologic evidence linking these viruses with human cancer occurrence, while adjusting for possible confounders, including workplace chemical carcinogens. We obtained interviews for 339 lung cancer deaths and 457 controls, selected from our combined cohorts of 30,411 poultry plant workers and 16,405 non-poultry workers, belonging to United Food & Commercial Workers unions. Data was analyzed by both logistic regression and Cox regression, adjusting for smoking and other confounders. Lung cancer risk was independently associated with tasks or work areas indicative of exposure to both poultry oncogenic viruses and to workplace chemical carcinogens. The study provides an incremental piece of evidence (epidemiologic), indirectly linking the oncogenic viruses of poultry with the occurrence of cancer in humans, and thus may have public health implications, but the limitations highlighted must be considered. Confirmatory studies, particularly molecular studies providing definitive proof of poultry oncogenic retrovirus integration in human DNA are needed, before the findings observed in this study can be put into proper perspective.