The potential for impact of man-made super low and extremely low frequency electromagnetic fields on sleep.

An ever-growing number of electromagnetic (EM) emission sources elicits health concerns, particularly stemming from the ubiquitous low to extremely low frequency fields from power lines and appliances, and the radiofrequency fields emitted from telecommunication devices. In this article we review the state of knowledge regarding possible impacts of electromagnetic fields on melatonin secretion and on sleep structure and the electroencephalogram of humans. Most of the studies on the effects of melatonin on humans have been conducted in the presence of EM fields, focusing on the effects of occupational or residential exposures. While some of the earlier studies indicated that EM fields may have a suppressive effect on melatonin, the results cannot be generalized because of the large variability in exposure conditions and other factors that may influence melatonin. For instance, exposure to radiofrequency EM fields on sleep architecture show little or no effect. However, a number of studies show that pulsating radiofrequency electromagnetic fields, such as those emitted from cellular phones, can alter brain physiology, increasing the electroencephalogram power in selective bands when administered immediately prior to or during sleep. Additional research is necessary that would include older populations and evaluate the interactions of EM fields in different frequency ranges to examine their effects on sleep in humans.

Relationships between greenness and low birth weight: Investigating the interaction and mediation effects of air pollution.

BACKGROUND: Associations between residential greenness and improved birth weight have been increasingly reported, but underlying mechanisms and interactions with other environmental exposures are still unclear. OBJECTIVES: To study the relationships between low birth weight (LBW, <2500 g), residential greenness, and the potential influence of air pollution in these relationships (interaction and mediation) in California, over the period 2001-2008. METHODS: Residential greenness around maternal homes was characterized using the Normalized Difference Vegetation Index (NDVI). Complementary indicators of air pollution exposure reflected its main components. Birth weight and maternal characteristics were obtained from birth certificate records. In this case-cohort study, associations between greenness and LBW were investigated using multi-level Poisson regression with random effect at the hospital level. We investigated potential interaction of greenness and air pollutants on both additive and multiplicative scales. Mediation analyses were conducted to estimate the potential contribution of local variations in air pollutant concentrations associated with greenness on LBW risk. RESULTS: In total 72,632 LBW cases were included. A reduction of LBW risk was associated with an increase in NDVI (adjusted risk ratio per inter-quartile range in NDVI: 0.963; 95% confidence interval: 0.947; 0.978). We observed no interaction between NDVI and air pollution on LBW risk. The estimated mediating effect of fine particulate matter in the impact of greenness on LBW was 12%. CONCLUSION: This large study confirms that residential greenness is associated with a reduced risk of LBW and suggests that greenness might benefit to LBW partly through a local reduction in air pollution.

Refining duration and frequency thresholds of restless legs syndrome diagnosis criteria.

OBJECTIVE: This study assesses the prevalence of restless legs syndrome (RLS) using DSM-5 criteria and determines what is the most appropriate threshold for the frequency and duration of RLS symptoms. METHODS: The Sleep-EVAL knowledge base system queried the interviewed subjects on life, sleeping habits, and health. Questions on sleep and mental and organic disorders (DSM-5, ICD-10) were also asked. A representative sample of 19,136 noninstitutionalized individuals older than 18 years living in the United States was interviewed through a cross-sectional telephone survey. The participation rate was 83.2%. RESULTS: The prevalence of the 4 leg symptoms describing RLS occurring at least 1 d/wk varied between 5.7% and 12.3%. When the frequency was set to at least 3 d/wk, the prevalence dropped and varied between 1.8% and 4.5% for the 4 leg symptoms. Higher frequency of leg symptoms was associated with greater distress and impairment with a marked increase at 3 d/wk. Symptoms were mostly chronic, lasting for more than 3 months in about 97% of the cases. The prevalence of RLS according to DSM-5 was 1.6% (95% confidence interval 1.4%-1.8%) when frequency was set at 3 d/wk. Stricter criteria for frequency of restless legs symptoms resulted in a reduction of prevalence of the disorder. The prevalence was further reduced when clinical impact was taken into consideration. CONCLUSIONS: In order to avoid inflation of case rates and to identify patients in whom treatment is truly warranted, using a more conservative threshold of 3 times or greater per week appears the most appropriate.

[DEFINITIONS AND EPIDEMIOLOGY OF EXCESSIVE SLEEPINESS]. / Définitions et épidémiologie de L'hypersomnolence. La plainte "somnolence excessive" concerne un quart de la population.

Excessive sleepiness or hypersomnolence is currently defined by two main symptoms: 1) the excessive amount of sleep, defined as a prolonged period of main sleep or the presence of naps; and 2) poor quality of awakening. Excessive sleepiness was reported by 27.8%. The presence of recurrent periods of irresistible sleep in the same day was found in 13.2%, recurrent naps in the same day in 1.9%, non-restorative sleep despite a nighttime sleep of more than 9 hours (0.7%), as well as a sleep drunkenness (4.4%). Adding criteria for duration and frequency (minimum of 3 times per week and duration of at least 3 months), having social or professional impairment and psychological distress, and after excluding significant associated comorbidities, the prevalence fall to 1.5%. These very important prevalence hypersomnolence figures constitute an excellent argument to educate doctors and health authorities on the need to identify and support the excessive sleepiness disorders.

Artificial Outdoor Nighttime Lights Associate with Altered Sleep Behavior in the American General Population.

STUDY OBJECTIVES: Our study aims to explore the associations between outdoor nighttime lights (ONL) and sleep patterns in the human population. METHODS: Cross-sectional telephone study of a representative sample of the general US population age 18 y or older. 19,136 noninstitutionalized individuals (participation rate: 83.2%) were interviewed by telephone. The Sleep-EVAL expert system administered questions on life and sleeping habits; health; sleep, mental and organic disorders (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; International Classification of Sleep Disorders, Second Edition; International Classification of Diseases, 10(th) Edition). Individuals were geolocated by longitude and latitude. Outdoor nighttime light measurements were obtained from the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS), with nighttime passes taking place between 19:30 and 22:30 local time. Light data were correlated precisely to the geolocation of each participant of the general population sample. RESULTS: Living in areas with greater ONL was associated with delayed bedtime (P < 0.0001) and wake up time (P < 0.0001), shorter sleep duration (P < 0.01), and increased daytime sleepiness (P < 0.0001). Living in areas with greater ONL also increased the dissatisfaction with sleep quantity and quality (P < 0.0001) and the likelihood of having a diagnostic profile congruent with a circadian rhythm disorder (P < 0.0001). CONCLUSIONS: Although they improve the overall safety of people and traffic, nighttime lights in our streets and cities are clearly linked with modifications in human sleep behaviors and also impinge on the daytime functioning of individuals living in areas with greater ONL.

Green spaces and pregnancy outcomes in Southern California.

Little is known about the impacts of green spaces on pregnancy outcomes. The relationship between green space exposure and preeclampsia has never been studied. We used a hospital-based perinatal database including more than 80,000 births to study the relationships between greenness exposure and three pregnancy outcomes: birth weight in term born infants, preterm deliveries and preeclampsia. Greenness was characterized using the normalized difference vegetation index (NDVI) within circular buffers surrounding maternal homes. Analyses were conducted using generalized estimating equations, adjusted for potential confounders. We observed an increase in birth weight in term born infants and a reduced risk of preterm births associated with an increase in NDVI. No significant association was observed between greenness and preeclampsia. This study provides modest support for beneficial effects of greenness exposure on pregnancy outcomes and calls for confirmation in other study settings.

Variations in atmospheric CO2 growth rates coupled with tropical temperature.

Previous studies have highlighted the occurrence and intensity of El Niño-Southern Oscillation as important drivers of the interannual variability of the atmospheric CO2 growth rate, but the underlying biogeophysical mechanisms governing such connections remain unclear. Here we show a strong and persistent coupling (r(2) ≈ 0.50) between interannual variations of the CO2 growth rate and tropical land-surface air temperature during 1959 to 2011, with a 1 °C tropical temperature anomaly leading to a 3.5 ± 0.6 Petagrams of carbon per year (PgC/y) CO2 growth-rate anomaly on average. Analysis of simulation results from Dynamic Global Vegetation Models suggests that this temperature-CO2 coupling is contributed mainly by the additive responses of heterotrophic respiration (Rh) and net primary production (NPP) to temperature variations in tropical ecosystems. However, we find a weaker and less consistent (r(2) ≈ 0.25) interannual coupling between CO2 growth rate and tropical land precipitation than diagnosed from the Dynamic Global Vegetation Models, likely resulting from the subtractive responses of tropical Rh and NPP to precipitation anomalies that partly offset each other in the net ecosystem exchange (i.e., net ecosystem exchange ≈ Rh - NPP). Variations in other climate variables (e.g., large-scale cloudiness) and natural disturbances (e.g., volcanic eruptions) may induce transient reductions in the temperature-CO2 coupling, but the relationship is robust during the past 50 y and shows full recovery within a few years after any such major variability event. Therefore, it provides an important diagnostic tool for improved understanding of the contemporary and future global carbon cycle.

Cytologic features of normal canine ovaries in different stages of estrus with histologic comparison.

BACKGROUND: Cytologic evaluation plays an important role in the diagnosis of ovarian neoplasia in dogs, but is supported by only scant information on cytologic features of canine ovaries. OBJECTIVE: The aim of this study was to provide detailed cytologic descriptions of normal canine ovaries in different stages of estrus with comparison to histologic features. METHODS: Client-owned dogs admitted for elective ovariohysterectomy were studied. For each dog, fine-needle aspirates of both ovaries were collected, stained, and examined and were compared with histologic sections of the same ovary. The stage of estrus was confirmed by examination of histologic sections and cytologic specimens of vaginal cells collected with swabs. RESULTS: Thirty-two ovaries from 16 dogs were examined. Luteal cells were observed in 82% of the dogs in diestrus. In early diestrus these cells were polygonal with amphophilic to deeply basophilic cytoplasm, and in late diestrus luteal cells had blebbed cell borders and clear cytoplasm with numerous small vacuoles. Perivascular arrangements and leuko-emperipolesis were noted in both phases of diestrus. Granulosa cells and spindle cells were found in cytologic specimens from most of the ovaries, and blue-gray extracellular material, sometimes associated with granulosa cells, was present. Medium-sized discrete round cells of undetermined origin were observed in some stages of estrus, and structures classified as corpora albicans were noted occasionally. CONCLUSIONS: Knowledge of specific cytologic features of normal canine ovaries is important for identification of pathologic processes in this organ. The novel findings of luteal cell emperipolesis, extracellular material associated with granulosa cells, and round cells of undetermined lineage warrant further study, which may provide new information on canine ovarian structure and function.

Global Distribution and Density of Constructed Impervious Surfaces.

We present the first global inventory of the spatial distribution and density ofconstructed impervious surface area (ISA). Examples of ISA include roads, parking lots,buildings, driveways, sidewalks and other manmade surfaces. While high spatialresolution is required to observe these features, the new product reports the estimateddensity of ISA on a one-km² grid based on two coarse resolution indicators of ISA - thebrightness of satellite observed nighttime lights and population count. The model wascalibrated using 30-meter resolution ISA of the USA from the U.S. Geological Survey.Nominally the product is for the years 2000-01 since both the nighttime lights andreference data are from those two years. We found that 1.05% of the United States landarea is impervious surface (83,337 km²) and 0.43 % of the world's land surface (579,703km²) is constructed impervious surface. China has more ISA than any other country(87,182 km²), but has only 67 m² of ISA per person, compared to 297 m² per person in theUSA. The distribution of ISA in the world's primary drainage basins indicates that watersheds damaged by ISA are primarily concentrated in the USA, Europe, Japan, China and India. The authors believe the next step for improving the product is to include reference ISA data from many more areas around the world.

Mapping and modeling the biogeochemical cycling of turf grasses in the United States.

Turf grasses are ubiquitous in the urban landscape of the United States and are often associated with various types of environmental impacts, especially on water resources, yet there have been limited efforts to quantify their total surface and ecosystem functioning, such as their total impact on the continental water budget and potential net ecosystem exchange (NEE). In this study, relating turf grass area to an estimate of fractional impervious surface area, it was calculated that potentially 163,800 km2 (+/- 35,850 km2) of land are cultivated with turf grasses in the continental United States, an area three times larger than that of any irrigated crop. Using the Biome-BGC ecosystem process model, the growth of warm-season and cool-season turf grasses was modeled at a number of sites across the 48 conterminous states under different management scenarios, simulating potential carbon and water fluxes as if the entire turf surface was to be managed like a well-maintained lawn. The results indicate that well-watered and fertilized turf grasses act as a carbon sink. The potential NEE that could derive from the total surface potentially under turf (up to 17 Tg C/yr with the simulated scenarios) would require up to 695 to 900 liters of water per person per day, depending on the modeled water irrigation practices, suggesting that outdoor water conservation practices such as xeriscaping and irrigation with recycled waste-water may need to be extended as many municipalities continue to face increasing pressures on freshwater.