4-Nonylphenol (NP) and bisphenol A (BPA) are phenolic substances used in high volumes by the industry. Studies on cells and in experimental animals have shown that both these compounds can be classified as estrogenic hormone disrupters. Information about the exposure of humans to NP and BPA is still scarce, especially regarding levels in human blood. The first aim of this study was to investigate possible sources of NP and BPA exposure from food, by analyzing the levels of NP and BPA from a Swedish food market basket, based on the Swedish per capita food consumption. A second aim was to investigate blood serum levels of NP and BPA, as well as NP-ethoxylates, among young women in Sweden (n=100). Moreover, associations between food consumption and blood NP and BPA levels were studied. In food, NP was to some extent found at levels above limit of quantification (LOQ 20 ng/g fresh weight) in fruits, cereal products, vegetables, and potatoes. BPA levels above LOQ (2 ng/g fresh weight) were found in fish, meats, potatoes, and dairy products. The estimated mean intakes per capita were (medium bound) 27 µg NP/day and 3.9 µg BPA/day, showing that food is a source of BPA and NP in the general Swedish population. In blood serum, free NP above limit of detection (LOD 0.5 ng/g) was detected in 46% of the study participants while detectable levels of total NP (LOD 0.8 ng/g) were observed in 43%. The corresponding percentages for BPA were 25% and 22%, respectively. The results indicate that there is a continuous source of exposure to NP and BPA that is high enough for free NP and BPA to be detected in some consumers. Among the participants with quantifiable levels of free and total NP (n=38), 85% (median, range: 38-112%) of the NP was present as free NP. For BPA 76% (49-109%) was detected as free BPA (n=15). All women had levels of ethoxylates of NP below LOD (0.1-0.7 ng/g). A significantly higher total consumption of fruits and vegetables was reported in questionnaires by participants with NP levels at or above LOD than among women with levels below LOD. This result is supporting the market basket results of relatively high NP levels in these types of food.
In May/June 2005 an outbreak of diarrhoeal illness occurred among company employees in Copenhagen. Cases were reported from seven of eight companies that received food from the same catering kitchen. Stool specimens from three patients from two companies were positive for Campylobacter jejuni. We performed a retrospective cohort study among employees exposed to canteen food in the three largest companies to identify the source of the outbreak and to prevent further spread. Using self-administered questionnaires we collected information on disease, days of canteen food eaten and food items consumed. The catering kitchen was inspected and food samples were taken. Questionnaires were returned by 295/348 (85%) employees. Of 247 employees who ate canteen food, 79 were cases, and the attack rate (AR) was 32%. Consuming canteen food on 25 May was associated with illness (AR 75/204, RR=3.2, 95%CI 1.3-8.2). Consumption of chicken salad on this day, but not other types of food, was associated with illness (AR=43/97, RR=2.3, 95%CI 1.3-4.1). Interviews with kitchen staff indicated the likelihood of cross-contamination from raw chicken to the chicken salad during storage. This is the first recognised major Campylobacter outbreak associated with contaminated chicken documented in Denmark. It is plausible that food handling practices contributed to transmission, and awareness of safe food handling and storage has since been raised among kitchen staff. The low number of positive specimens accrued in this outbreak suggests a general underascertainment of adult cases in the laboratory reporting system by a factor of 20.
Erratum In: Euro Surveill. 2006 May;11(5):1 p following 139
In November-December 2008, Norway and Denmark independently identified outbreaks of Salmonella Typhimurium infections characterised in the multiple-locus variable number of tandem repeats analysis (MLVA) by a distinct profile. Outbreak investigations were initiated independently in the two countries. In Denmark, a total of 37 cases were identified, and multiple findings of the outbreak strain in pork and pigs within the same supply chain led to the identification of pork in various forms as the source. In Norway, ten cases were identified, and the outbreak investigation quickly indicated meat bought in Sweden as the probable source and the Swedish authorities were alerted. Investigations in Sweden identified four human cases and two isolates from minced meat with the distinct profile. Subsequent trace-back of the meat showed that it most likely originated from Denmark. Through international alert from Norway on 19 December, it became clear that the Danish and Norwegian outbreak strains were identical and, later on, that the source of the outbreaks in all three countries could be traced back to Danish pork. MLVA was instrumental in linking the outbreaks in the different countries and tracing the source. This outbreak illustrates that good international communication channels, early alerting mechanisms, inter-sectoral collaboration between public health and food safety authorities and harmonised molecular typing tools are important for effective identification and management of cross-border outbreaks. Differences in legal requirements for food safety in neighbouring countries may be a challenge in terms of communication with consumers in areas where cross-border shopping is common.
Overland transport of ore concentrate from the Red Dog lead/zinc mine in northwest Alaska to its seaport has historically raised concerns among local subsistence users regarding the potential impacts of fugitive dust from the operation, including the potential uptake of metals into caribou meat. Caribou are an integral part of life for northern Alaska Natives for both subsistence and cultural reasons. The Western Arctic caribou herd, whose range includes the Red Dog mine, transportation corridor, and port site, sometimes overwinter in the vicinity of mine operations. A weight of evidence approach using multiple lines of evidence was used to evaluate potential risks associated with subsistence consumption of caribou harvested near the road and mine. Data from a long-term caribou monitoring program indicate a lack of consistent trends for either increasing or decreasing metals concentrations in caribou muscle, liver, and kidney tissue. Lead, cadmium, and zinc from all tissues were within the range of reference concentrations reported for caribou elsewhere in Northern Alaska. In addition, a site use study based on data from satellite-collared caribou from the Western Arctic Herd showed that caribou utilize the area near the road, port, and mine approximately 1/20th to 1/90th of the time assumed in a human health risk assessment conducted for the site, implying that risks were significantly overestimated in the risk assessment. The results from multiple lines of evidence consistently indicate that fugitive dust emissions from Red Dog Operations are not a significant source of metals in caribou, and that caribou remain safe for human consumption.
Recent evidence suggests an association between persistent organic pollutants (POPs) and type 2 diabetes. In two First Nations communities where wild food is consumed by a large portion of the population, we compared pollutants in plasma between diabetic and non-diabetic individuals, and investigated the strength of association between pollutants and insulin resistance/secretion in non-diabetic individuals.
The study population consisted of 72 participants. Oral Glucose Tolerance Tests were used to assess diabetes status. Plasma was used to determine POP concentrations and mercury concentrations were determined from hair samples.
Age-adjusted plasma concentrations of some pollutants were significantly higher in diabetic than in non-diabetic individuals. When taking into account age, adiposity levels, and smoking status, POP levels were not associated with insulin resistance nor with insulin secretion in non-diabetic individuals.
These findings confirm that POP concentrations in plasma may be higher in diabetic than in non-diabetic individuals. No association was however seen between POP concentrations and markers of insulin resistance/secretion in non-diabetic individuals.
The toxic metal cadmium is suggested to increase the risk of cardiovascular disease, but only one incidence study has explored this association. We evaluated the association between quartiles of food frequency questionnaire-based estimates of cadmium exposure from food (the predominant source of exposure to the metal) and incident cardiovascular disease and its subtypes.
From the population-based Swedish Mammography cohort, 33,333 women were followed prospectively from baseline (1997) through 2010. We estimated relative risks (RRs) with 95% confidence intervals (CIs) using Cox proportional hazard models.
During 12 years of follow-up, we identified 3155 incident cases of total cardiovascular disease (1322 cases of myocardial infarction and 1833 cases of total stroke [1485 ischemic and 208 hemorrhagic stroke]). Dietary cadmium exposure was not associated with risk of total cardiovascular disease, myocardial infarction, or total stroke or its subtypes. For total cardiovascular disease, the multivariable-adjusted RR comparing the highest quartile of cadmium exposure with the lowest was 0.96 (95% CI = 0.85-1.09). The corresponding RRs were 1.07 (0.88-1.29) for myocardial infarction, 0.90 (0.76-1.05) for total stroke, 0.89 (0.74-1.06) for ischemic stroke, and 1.11 (0.68-1.80) for hemorrhagic stroke.
Our study lends no support to an overall association between low-level exposure to cadmium via food and incident cardiovascular disease.
Previous outbreaks of Salmonella Enteritidis in Canada and the United States have been associated with the consumption of almonds. From December 2005 to August 2006 a cluster of 15 cases of Salmonella Enteritidis NST 3+ was reported in Sweden. A case-control study was performed to identify the source of transmission. Three controls per case were randomly selected, matched on sex, age and place of residence. Cases and controls were interviewed by telephone and data were analysed with a conditional logistic model. The results showed that eating almonds was a risk factor for infection with Salmonella Enteritidis NST3+ (unmatched odds ratio 45.0, 95% confidence interval: 4.8-421.8). No Salmonella was isolated from almonds tested in the study. In conclusion, almonds could be the source of the outbreak and should be considered when investigating outbreaks as well as sporadic cases of Salmonella Enteritidis.