Predicting the impact and duration of persistent and mobile organic compounds in groundwater systems using a contaminant mass discharge approach.

This study investigated methods for predicting the duration and impact on groundwater quality from persistent and mobile organic compounds (PMOCs) at a drinking water well field affected by multiple contaminant sources. The fungicide metabolite N,N-dimethylsulfamide (DMS), which frequently occurs above the Danish groundwater quality criterion (0.1 µg/L), was used as an example. By combining contaminant mass discharge (CMD) estimations, modeling, and groundwater dating, a number of important discoveries were made. The current center of contaminant mass was located near the source area. The CMD at the well field was predicted to peak in 2040, and an effect from the investigated sources on groundwater quality could be expected until the end of the 21st century. A discrepancy in the current CMD at the well field and the estimated arrival time from the studied source area suggested an additional pesticide source, which has not yet been thoroughly investigated. The presence of the unknown source was supported by model simulations, producing an improved mass balance after inclusion of a contaminant source closer to the well field. The approach applied here was capable of predicting the duration and impact of DMS contamination at a well field at catchment scale. It furthermore shows potential for identification and quantification of the contribution from individual sources, and is also applicable for other PMOCs. Predicting the duration of the release and impact of contaminant sources on abstraction wells is highly valuable for water resources management and authorities responsible for contaminant risk assessment, remediation, and long-term planning at water utilities.

Long-term leaching through clayey till of N,N-dimethylsulfamide, a Persistent and Mobile Organic Compound (PMOC).

Environmental pollution with Persistent and Mobile Organic Compounds (PMOC) from anthropogenic activities is an increasing cause for concern. These compounds are readily leached to groundwater aquifers and are likely to resist degradation, putting pressure on groundwater resources. Pesticides can form PMOCs upon degradation in the environment. The PMOC N,N-dimethylsulfamide (DMS) was the most frequently detected pesticide metabolite in Danish drinking water wells in 2020, although the pesticidal use of the last parent compound (tolylfluanid) ended in 2007. This study aimed to improve the understanding of the leaching of the PMOC DMS from clayey tills by combining a review of compound properties, sources and use, comprehensive field observations and numerical flow and solute transport modeling. The modeling explored the mechanisms of DMS retention during vertical transport in clayey till and the fingerprint in the underlying aquifer. The results were supported by detailed field observations at an agricultural site with strawberry production. Porewater samples were collected from clayey till to a depth of 12 m bgs by a custom designed installation method of suction cups. Groundwater sampling (249 samples) was designed to provide vertical concentration profiles at various distances from the presumed sources. The review of properties showed that the parent compounds and intermediates degrade quickly in topsoil, releasing the highly persistent and mobile DMS. We tested the effect of fractures on transport with different hydraulic apertures and a scenario without fractures by numerical modeling. The results showed that the presence of fractures can smooth the breakthrough curve below the clayey till, leading to faster breakthrough, lower maximum concentration, and several decades of prolonged leaching in simulations with the largest aperture (20 µm). The fracture-matrix interaction is a possible explanation for the observed delay of leaching from clayey till. The vertical concentration profiles in groundwater were used for identifying the sources at the field site and testing source strengths. Assigning one point source (200 µg/L) and two diffuse sources (40-50 µg/L) to the model produced vertical concentration profiles that compared well with observed field data in clayey till and the aquifer. All results were integrated into a conceptual model for the environmental fate of PMOCs in soil and groundwater. The findings of this study imply that the presence of fractures in clayey till should be considered in conceptual site models, since they can substantially prolong the leaching of PMOCs to groundwater. The integration of comprehensive field investigations and numerical modeling is key to understand the fate of PMOCs in complex field systems with different source types. Together with widespread occurrences of PMOCs in groundwater systems, the results highlight the need for improved approval procedures for pesticides and biocides which considers their persistent and mobile metabolites.

Development of video tutorials to help parents manage children with acute illnesses using a modified Delphi method.

AIM: Children often fall sick, which causes concern among parents. Online health information can be confusing and difficult to understand. We aimed to produce simple, informative video tutorials on the symptoms ill children present. METHODS: We used a modified Delphi method to produce video tutorials on the symptoms of fever, vomiting and diarrhoea, abdominal pain, breathing difficulties, sore throat, red eyes, earache and rash. We identified the most common symptoms in acutely ill children. During the first consensus round, experts rated statements on out-of-hospital management from existing health information. Video tutorials were produced from statements rated to be included. The second consensus round involved video showings and editing. Two videos were evaluated in focus groups by parents. RESULTS: During the first round, experts rated a median of 79 (40-154) statements for each symptom. Panels consisted of a median of seven (6-11) experts, primarily. Panels reached a consensus on inclusion, neutrality or exclusion in 83% of statements. The second round led to adjustments to the videos and final approval by experts. Most parents evaluated the videos as 'informative, easy to understand and calming'. CONCLUSION: We produced video tutorials on the common symptoms ill children present using a modified Delphi method. Feedback from parents in focus groups was positive.

Prenatal exposure to airborne polychlorinated biphenyl congeners and male reproductive health.

STUDY QUESTION: Is fetal exposure to lower-chlorinated polychlorinated biphenyls (LC-PCBs) in indoor air of private homes built with PCB-containing materials associated with semen characteristics and testicular volume in adult men? SUMMARY ANSWER: We observed only marginal and inconsistent associations between maternal exposure to PCBs in indoor air and semen quality, testicular size and reproductive hormones in the adult offspring. WHAT IS KNOWN ALREADY: Recent studies have shown LC-PCBs to exhibit endocrine-disrupting properties and increase the risk of cryptorchidism. Although exposure to LC-PCBs in indoor air is relatively common, the long-term impact of prenatal exposure on male reproductive health has not yet been investigated. STUDY DESIGN, SIZE, DURATION: In this cohort study, participants were men (18+ years) whose mothers carried them while living in one of two residential areas where indoor air had been contaminated by LC-PCB evaporating from building materials in subsets of the apartments. Men were considered prenatally exposed if their mother had lived in a PCB-contaminated apartment and unexposed if their mother had lived in an uncontaminated apartment for a minimum of 1 year during the 3.6 years before conception or during the first trimester. Mothers of prenatally unexposed men could not have lived in a contaminated apartment at any point. Recruitment lasted from 2017 to 2019. In total, 73 exposed and 111 unexposed men gave a blood and semen sample. PARTICIPANTS/MATERIALS, SETTING, METHODS: Percentage differences in semen volume, sperm concentration, total sperm count, morphologically normal spermatozoa, progressively motile spermatozoa and DNA fragmentation index (DFI) between prenatally exposed and unexposed men were estimated using negative binomial regression. Associations with total and calculated free testosterone (CFT), LH and FSH were modeled using the linear regression. Odds of small testicular volume was estimated with logistic regression. MAIN RESULTS AND THE ROLE OF CHANCE: Overall, the results of this study were conflicting. No differences in semen volume, sperm concentration, testosterone and CFT were observed between the groups, but there were slight indications of lower total sperm count, increased FSH and risk of small testicles, alongside lower sperm DFI and a higher proportion of normal spermatozoa in men exposed to LCB-PCBs from indoor air during fetal life. There is no apparent biologically plausible explanation for the apparently improved measures of DNA fragmentation and morphology, and these findings may have occurred purely by chance. LIMITATIONS, REASONS FOR CAUTION: Owing to the indirect measure of exposure, lack of adjustment for paternal factors, the potential for self-selection due to known exposure status and fertility issues, inability to take time spent away from the residence, limited statistical power and lack of comparable literature, independent replication of the study in larger cohorts is warranted. WIDER IMPLICATIONS OF THE FINDINGS: While our findings may appear reassuring for the large number of people residing and/or working in buildings with indoor air contaminated with LC-PCBs, further efforts to understand the full range of health consequences of fetal LC-PCB exposure are needed. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by the Independent Research Fund Denmark (ref no. 6110-00085B), Bispebjerg Hospital, Landsbyggefonden, Realdania (ref. no. PRJ-2017-00176), Grundejernes Investeringsfond (ref. no. 18-58) and Helsefonden (ref. no. 16-B-01-22 and 21-B-0412). K.S.H. was supported by FFIKA, Focused Research Effort on Chemicals in the Working Environment, from the Danish Government. The authors declare that they have no financial, personal or professional competing interests. TRIAL REGISTRATION NUMBER: Not applicable.

Risk assessment of consumer spray products using in vitro lung surfactant function inhibition, exposure modelling and chemical analysis.

Consumer spray products release aerosols that can potentially be inhaled and reach the deep parts of the lungs. A thin layer of liquid, containing a mixture of proteins and lipids known as lung surfactant, coats the alveoli. Inhibition of lung surfactant function can lead to acute loss of lung function. We focused on two groups of spray products; 8 cleaning and 13 impregnation products, and in the context of risk assessment, used an in vitro method for assessing inhibition of lung surfactant function. Original spray-cans were used to generate aerosols to measure aerodynamic particle size distribution. We recreated a real-life exposure scenario to estimate the alveolar deposited dose. Most impregnation products inhibited lung surfactant function at the lowest aerosolization rate, whereas only two cleaning products inhibited function at the highest rates. We used inhibitory dose and estimated alveolar deposition to calculate the margin of safety (MoS). The MoS for the inhibitory products was ≤1 for the impregnation products, while much larger for the cleaning products (>880). This risk assessment focused on the risk of lung surfactant function disruption and provides knowledge on an endpoint of lung toxicity that is not investigated by the currently available OECD test guidelines.

Measurement of dust-borne MRSA in pig farms using different approaches.

AIMS: To obtain knowledge about (i) how to sample airborne methicillin-resistant Staphylococcus aureus (MRSA) and dust in the pig farm environment including effects of sampler on (a) measured exposure, (b) MRSA survival and (c) spatial and temporal variation in exposure, and (ii) the association between exposure to MRSA, dust and optical density OD. METHODS AND RESULTS: Airborne dust was sampled on five pig farms using five active and one passive samplers. Staphylococcus aureus and MRSA (as a subset of S. aureus) were quantified using selective agar media and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The Andersen sampler, electrostatic dust collectors (EDC), and Gesamtstaubprobenahme (GSP) and Institute of Occupational Medicine samplers with polycarbonate or Teflon filters were applicable for sampling airborne MRSA. The half-life of MRSA was not reduced by active sampling. A significant correlation was found between dust and S. aureus exposure within, but not between, farm section and farms. A significant spatial and temporal variation in dust and MRSA exposure was found within a stable. The dust sampling rate and the concentration of MRSA in the sampled dust decreased after 5 days of sampling. CONCLUSION: Sampling using the GSP can be performed for 1 h without affecting the following half-life of MRSA. Sampling for MRSA using the EDC should not exceed 3 days due to overloading and the die-off of MRSA. The measurement of OD may be used as a proxy measure for dust exposure. To obtain knowledge about potential exposure, samples should be taken repeatedly and in different areas within a stable section. SIGNIFICANCE AND IMPACT OF THE STUDY: Sampling method, sampling time and number of samples taken, but not force of airflow on the filter, influence the measured potential exposure to MRSA and dust.

Effect of high-intensity training versus moderate training on peak oxygen uptake and chronotropic response in heart transplant recipients: a randomized crossover trial.

In heart transplant (HTx) recipients, there has been reluctance to recommend high-intensity interval training (HIIT) due to denervation and chronotropic impairment of the heart. We compared the effects of 12 weeks' HIIT versus continued moderate exercise (CON) on exercise capacity and chronotropic response in stable HTx recipients >12 months after transplantation in a randomized crossover trial. The study was completed by 16 HTx recipients (mean age 52 years, 75% males). Baseline peak oxygen uptake (VO2peak ) was 22.9 mL/kg/min. HIIT increased VO2peak by 4.9 ± 2.7 mL/min/kg (17%) and CON by 2.6 ± 2.2 mL/kg/min (10%) (significantly higher in HIIT; p < 0.001). During HIIT, systolic blood pressure decreased significantly (p = 0.037) with no significant change in CON (p = 0.241; between group difference p = 0.027). Peak heart rate (HRpeak ) increased significantly by 4.3 beats per minute (p = 0.014) after HIIT with no significant change in CON (p = 0.34; between group difference p = 0.027). Heart rate recovery (HRrecovery ) improved in both groups with a trend toward greater improvement after HIIT. The 5-month washout showed a significant loss of improvement. HIIT was well tolerated, had a superior effect on oxygen uptake, and led to an unexpected increase in HRpeak accompanied by a faster HRrecovery . This indicates that the benefits of HIIT are partly a result of improved chronotropic response.

What women want. Women's preferences for the management of low-grade abnormal cervical screening tests: a systematic review.

BACKGROUND: If human papillomavirus (HPV) testing will replace cytology in primary cervical screening, the frequency of low-grade abnormal screening tests will double. Several available alternatives for the follow-up of low-grade abnormal screening tests have similar outcomes. In this situation, women's preferences have been proposed as a guide for management decisions. OBJECTIVES: To determine women's preferences for the follow-up of low-grade cervical screening abnormalities. SEARCH STRATEGY: Using Medical Subject Headings (MeSH) terms, PubMed was searched for articles published up to December 2010. The reference lists of the retrieved studies were consulted. SELECTION CRITERIA: Studies asking women to state a preference between active follow-up and observation for the management of low-grade abnormalities on screening cytology or HPV tests. DATA COLLECTION AND ANALYSIS: Information on study design, participants and outcomes was retrieved using a prespecified form. Studies were sorted by design. MAIN RESULTS: Thirteen studies were included in the review. In all five studies that surveyed women with abnormal tests before any management had started, two-thirds preferred active follow-up, predominantly as immediate colposcopy, to observation, predominantly as repeated Pap smears. In all but two studies testing other situations, women more often expressed a preference for active follow-up than for observation; however, women appeared to be somewhat more willing to accept observation if reassured of the low risk of cervical cancer. CONCLUSIONS: Even for low-grade abnormal cervical tests, women tend to prefer active management strategies. It may be a challenge to meet their expectations of optimal follow-up when HPV testing is used in primary screening.

The demographic impact of extreme events: stochastic weather drives survival and population dynamics in a long-lived seabird.

1. Most scenarios for future climate change predict increased variability and thus increased frequency of extreme weather events. To predict impacts of climate change on wild populations, we need to understand whether this translates into increased variability in demographic parameters, which would lead to reduced population growth rates even without a change in mean parameter values. This requires robust estimates of temporal process variance, for example in survival, and identification of weather covariates linked to interannual variability. 2. The European shag Phalacrocorax aristotelis (L.) shows unusually large variability in population size, and large-scale mortality events have been linked to winter gales. We estimated first-year, second-year and adult survival based on 43 years of ringing and dead recovery data from the Isle of May, Scotland, using recent methods to quantify temporal process variance and identify aspects of winter weather linked to survival. 3. Survival was highly variable for all age groups, and for second-year and adult birds process variance declined strongly when the most extreme year was excluded. Survival in these age groups was low in winters with strong onshore winds and high rainfall. Variation in first-year survival was not related to winter weather, and process variance, although high, was less affected by extreme years. A stochastic population model showed that increasing process variance in survival would lead to reduced population growth rate and increasing probability of extinction. 4. As in other cormorants, shag plumage is only partially waterproof, presumably an adaptation to highly efficient underwater foraging. We speculate that this adaptation may make individuals vulnerable to rough winter weather, leading to boom-and-bust dynamics, where rapid population growth under favourable conditions allows recovery from periodic large-scale weather-related mortality. 5. Given that extreme weather events are predicted to become more frequent, species such as shags that are vulnerable to such events are likely to exhibit stronger reductions in population growth than would be expected from changes in mean climate. Vulnerability to extreme events thus needs to be accounted for when predicting the ecological impacts of climate change.

A needed information source.

Most sources of information regarding drugs in pregnancy include information on whether a drug causes congenital anomalies and whether a drug causes changes in fetal function or neonatal adaptation. Therapeutic issues related to the treatment of maternal disease are not readily available. Despite known physiologic changes of pregnancy, drug dosages are widely assumed to be the same as the healthy adult. An informational source is needed which addresses the therapeutic issues of pregnant women.

Spontaneously reported adverse reactions after diphtheria-tetanus revaccination at 4-6 years of age--a comparison of two vaccines with different amounts of diphtheria toxoid.

On 1 January 1996, diphtheria-tetanus revaccination at the age of 5 years was implemented in the Danish Childhood Vaccination Programme. Initially, a combined DT vaccine containing 25 Lf diphtheria toxoid was used. Due to a high frequency of spontaneously reported adverse reactions, however, concerns were raised that the diphtheria dose was too high, and it was reduced to 6.25 Lf. This survey presents the rates of spontaneously reported adverse reactions following diphtheria-tetanus revaccinations of 4-6-year-old from 1996 to 2002. The change to the lower dose of diphtheria toxoid resulted in a remarkable reduction in the yearly rates of injection site reactions: in 1996, the rate was 180 injection site reactions per 100,000 vaccinations; from 1998 to 2002, this changed to between 12 and 24 reactions per 100,000 vaccinations. Furthermore, the rates of systemic reactions such as fever were reduced.

Scientific analysis of phenol nail surgery.

Chemical matrixectomy using phenol is one of the most common surgical procedures for the permanent removal of toenails. The concentration of phenol solution and duration of its application have varied widely and have not been subjected to scientific study. The authors studied the histologic effects of phenol on the nail matrix and determined the optimal concentration of phenol and time the phenol solution needs to be in contact with the nail bed.

Conspecific reproductive success affects age of recruitment in a great cormorant, Phalacrocorax carbo sinensis, colony.

Few studies have addressed the proximate factors affecting the age at which individuals of long-lived bird species are recruited into the breeding population. We use capture-recapture analysis of resightings of 16 birth cohorts of colour-ringed great cormorants, Phalacrocorax carbo sinensis, in a Danish colony to assess the evidence for two hypotheses: conspecific attraction (earlier recruitment when the colony is large) and conspecific reproductive success (earlier recruitment following years of high breeding success). For both males and females, conspecific reproductive success was the most important covariate explaining the interannual variation in age of recruitment; colony size was also important for females. These covariates explained nearly 60% of the year-to-year variation for both sexes. The age of recruitment increased for cohorts born after 1990, and this increase was correlated with a decline in breeding success in the colony; we interpret this as an indirect and delayed density-dependent effect. Females were recruited earlier than males (mean age of recruitment for cohorts born before 1990: 2.98 years versus 3.53 years); the most plausible reason for this is a skewed sex ratio in favour of males in the adult population. Recruitment of males may thus, to some extent, be constrained by the availability of females. This study provides the first evidence that conspecific reproductive success can affect the age at which individual birds start to breed.

Physiologic changes in pregnancy and their effect on drug disposition.

Changes in maternal physiology occur normally during pregnancy and have the potential to alter the absorption, distribution, and elimination of drugs used therapeutically in pregnant women. These physiologic changes include: plasma volume expansion and increases in extracellular fluid space and total body water; decreased plasma albumin concentration; a compensated respiratory alkalosis; increased cardiac output with regional blood flow changes; increased renal blood flow associated with increased glomerular filtration; changes in hepatic drug metabolizing enzymes; and changes in gastrointestinal function. These changes begin in early gestation but are most pronounced in the third trimester of pregnancy. Further maternal physiologic changes occur intrapartum with some normalizing themselves within 24 hours of delivery, while others are sustained only returning to normal some 12 weeks postpartum. These physiologic changes form the basis for the need for pharmacokinetic studies during pregnancy.

A randomized trial of misoprostol versus extra-amniotic sodium chloride infusion with oxytocin for induction of labor.

OBJECTIVE: Our purpose was to compare the efficacy and safety of misoprostol and extra-amniotic sodium chloride infusion with oxytocin for induction of labor. STUDY DESIGN: This randomized trial compared two methods of labor induction in women requiring cervical ripening. One hundred twenty-three women undergoing labor induction with a Bishop score < or =5 were randomly selected to receive either misoprostol, 50 microg intravaginally every 4 hours, or extra-amniotic sodium chloride infusion. The primary outcome variable was the time interval from induction to vaginal delivery. RESULTS: Sixty-one women received extra-amniotic sodium chloride infusion and 62 women received misoprostol. The mean time interval from the start of induction to vaginal delivery was 15.0 +/- 5.0 hours and 16.5 +/- 7.2 hours for the extra-amniotic infusion and misoprostol groups, respectively (P, not significant). The cesarean delivery rate was not significantly different between the 2 groups (32.8% for the extra-amniotic infusion group; 19.4% for the misoprostol group). Maternal and neonatal outcomes were similar between the 2 groups. CONCLUSIONS: Both methods of induction are equally efficacious and result in similar maternal and neonatal outcomes.

Placenta previa: a 22-year analysis.

OBJECTIVE: Our purpose was to identify what anesthetic method is safer for women with a placenta previa. STUDY DESIGN: We retrospectively reviewed all women with placenta previa who underwent cesarean delivery during the period January 1, 1976-December 31, 1997 at Northwestern Memorial Hospital. RESULTS: Of 93,384 deliveries, placenta previa was found in 514 women. Identifiable trends with time included an increasing incidence of placenta previa (r = 0.54, P <.01); cesarean hysterectomy (r = 0.54, P <.01); placenta accreta (r = 0.45, P <.03); and regional anesthesia (r = 0.84, P <.0001). The mean gestational age at delivery was 35.3 +/- 3.4 weeks and did not change with time. General anesthesia was used for delivery in 380 women and regional anesthesia was used for 134 women. Prior cesarean delivery and general anesthesia were independent predictors of the need for blood transfusion, but only prior cesarean delivery was a predictor of the need for hysterectomy. General anesthesia increased the estimated blood loss, was associated with a lower postoperative hemoglobin concentration, and increased the need for blood transfusion. Elective and emergent deliveries did not differ in estimated blood loss, in postoperative hemoglobin concentrations, or in the incidence of intraoperative and anesthesia complications. Regional and general anesthesia did not differ in the incidence of intraoperative and anesthesia complications. CONCLUSIONS: In women with placenta previa, general anesthesia increased intraoperative blood loss and the need for blood transfusion. Regional anesthesia appears to be a safe alternative.

Fetal heart rate characteristics at 25 to 28 weeks' gestation.

The objective of this article is to define normative fetal heart rate (FHR) tracing characteristics between 25-28 weeks' gestation in a low-risk population with normal pregnancy outcomes and to determine which criteria best determine FHR reactivity. Continuous FHR tracings were reviewed from 188 low-risk women participating in a trial of the Mammary Stimulation Test (MST) at 25-28 weeks' gestation. A reactive tracing required the presence of > or =two accelerations in 20 min. Different acceleration criteria were evaluated based upon the width of the acceleration (short vs. long) and the amplitude of the acceleration (10 vs. 15 bpm). Seventy-one percent of the FHR tracings were reactive using the higher amplitude (15 bpm), short criteria. This number increased significantly to 92% when the lower amplitude (10 bpm), short criteria were used (p <0.01). As gestational age advanced, there was a trend toward increased reactivity irrespective of which criteria were used, but these differences were not significant. Reducing the acceleration amplitude criteria to 10 bpm in preterm pregnancies will maximize the number of reactive nonstress tests. This is advantageous because it would improve test specificity and decrease the false-positive rate. Our findings need to be prospectively validated in a high-risk population.

Management of twin pregnancies consisting of a complete hydatidiform mole and normal fetus.

OBJECTIVE: To report the clinical features, management, and outcome of twin pregnancies consisting of a complete hydatidiform mole and a coexisting normal fetus. METHODS: Between 1966 and 1997, seven women with complete hydatidiform mole and coexisting normal fetus were treated at the John I. Brewer Trophoblastic Disease Center of Northwestern University Medical School. Clinical features, including presenting symptoms, gestational dates, hCG levels, and complications, as well as route of delivery or evacuation, pregnancy outcome, genetic analysis, and need for chemotherapy were assessed. RESULTS: Four women required uterine evacuation before 20 weeks' gestation because of vaginal bleeding or medical complications, one woman required an emergency hysterotomy because of hemorrhage at 24 weeks, and two women delivered normal, viable infants at 26 and 34 weeks. The pathologic diagnosis of complete hydatidiform mole was confirmed in each case and the chromosome complement was 46,XX in all molar gestations. Four of seven women required chemotherapy for treatment of nonmetastatic gestational trophoblastic tumors, including both women who delivered viable infants and two of the five women whose pregnancies were evacuated before 24 weeks' gestation. All four patients were treated with five to seven cycles of a 5-day methotrexate regimen and achieved complete remission. CONCLUSION: Patients with a twin pregnancy consisting of a complete mole and a normal fetus are at increased risk for hemorrhage and medical complications, as well as the development of persistent gestational trophoblastic tumor.