Effects of ultraviolet LED versus incandescent bulb and carbon dioxide for sampling abundance and diversity of Culicoides in Florida.

Biting midges (Ceratopogonidae: Culicoides) are vectors of bluetongue virus and epizootic hemorrhagic disease virus which cause significant morbidity and mortality in ruminants. Recently, ultraviolet light emitting diodes (UV/LEDs) in conjunction with suction traps have been widely utilized for Culicoides spp. collections. Despite the use of these traps, limited work has been done comparing sampling variability associated with these light types with and without CO2. For this objective, mini-CDC light traps with four different attractant combinations were operated at eight sites across Florida between April and October 2017. Trap attractants included white-incandescent lights and UV/LEDs with and without CO2 to determine optimum combinations of light type and attractant for species richness, diversity, and abundance of Culicoides spp. in Florida. The results of the study demonstrate that traps with UV/LED light collect greater richness, diversity, and abundance of Culicoides species than traps with white-incandescent light. Addition of CO2 resulted in greater diversity in traps with UV/LED lights, but lower diversity in traps with white-incandescent light. Therefore, CO2 may be used to increase the abundance of Culicoides spp. collected by traps, regardless of light type, but the ability for CO2 to attract a higher number and diversity of species to traps varies by the light type used. Therefore, we suggest using CO2 primarily in conjunction with UV/LED light. When CO2 is not available, UV/LED light used alone can be substituted without a significant loss in species richness or diversity, although abundance of most Culicoides species will be significantly lower in the absence of CO2.

Centers for Disease Control-type light traps equipped with high-intensity light-emitting diodes as light sources for monitoring Anopheles mosquitoes.

In this study the phototactic response of anopheline mosquitoes to different luminous intensity light-emitting diodes (LEDs) was investigated. Centers for Disease Control-type light traps were changed by replacement of the incandescent lamps by 5 mm round type green (520 nm) and blue (470 nm) LEDs of different luminous intensities: green-LED traps with luminous intensities of 10,000, 15,000 and 20,000 millicandela (mcd) and the blue-LED traps with luminous intensities of 4000, 12,000 and 15,000 mcd. Our data showed that increasing luminous intensity has an effect on the attraction of anopheline mosquitoes to light traps, highlighting the importance of taking LEDs and light sources of high luminous intensity into account when using light-trap collections in monitoring populations of Anopheles species.

Disparity in Cutaneous Pigmentary Response to LED vs Halogen Incandescent Visible Light: Results from a Single Center, Investigational Clinical Trial Determining a Minimal Pigmentary Visible Light Dose.

Background: While most of the attention regarding skin pigmentation has focused on the effects of ultraviolet radiation, the cutaneous effects of visible light (400 to 700nm) are rarely reported. OBJECTIVE: The purpose of this study was to investigate the cutaneous pigmentary response to pure visible light irradiation, examine the difference in response to different sources of visible light irradiation, and determine a minimal pigmentary dose of visible light irradiation in melanocompetent subjects with Fitzpatrick skin type III - VI. METHODS: The study was designed as a single arm, non-blinded, split-side dual intervention study in which subjects underwent visible light irradiation using LED and halogen incandescent light sources delivered at a fluence of 0.14 Watts/cm2 with incremental dose progression from 20 J/cm2 to 320 J/cm2. Pigmentation was assessed by clinical examination, cross-polarized digital photography, and analytic colorimetry. RESULTS: Immediate, dose-responsive pigment darkening was seen with LED light exposure in 80% of subjects, beginning at 60 Joules. No pigmentary changes were seen with halogen incandescent light exposure at any dose in any subject. CONCLUSION: This study is the first to report a distinct difference in cutaneous pigmentary response to different sources of visible light, and the first to demonstrate cutaneous pigment darkening from visible LED light exposure. Our findings raise the concern that our increasing daily artificial light surroundings may have clandestine effects on skin biology.

J Drugs Dermatol. 2017;16(11):1105-1110.

Blue-Light Hazard From Gas Metal Arc Welding of Aluminum Alloys.

OBJECTIVES: The objective was to quantify the blue-light hazard from gas metal arc welding (GMAW) of aluminum alloys. The exposure level is expected to depend on the welding conditions. Therefore, it is important to identify the blue-light hazard under various welding conditions. METHODS: We experimentally conducted GMAW of aluminum alloys under various welding conditions and measured the spectral radiance of the arcs. The effective blue-light radiance, which the American Conference of Governmental Industrial Hygienists has defined to quantify the exposure level of blue light, was calculated from the measured spectral radiance. The maximum acceptable exposure duration per 10000 s for this effective blue-light radiance was calculated. RESULTS: The effective blue-light radiance measured in this study was in the range of 2.9-20.0 W cm-2·sr. The corresponding maximum acceptable exposure duration per 10000 s was only 5.0-34 s, so it is hazardous to view the welding arc. The effective blue-light radiance was higher at higher welding currents than at lower welding currents, when pulsed welding currents were used rather than steady welding currents, and when magnesium was included in the welding materials. CONCLUSIONS: It is very hazardous to view the arcs in GMAW of aluminum alloys. Welders and their helpers should use appropriate eye protection in arc-welding operations. They should also avoid direct light exposure when starting an arc-welding operation.

Field evaluation of a new light trap for phlebotomine sand flies.

Light traps are one of the most common attractive method for the collection of nocturnal insects. Although light traps are generally referred to as "CDC light traps", different models, equipped with incandescent or UV lamps, have been developed. A new light trap, named Laika trap 3.0, equipped with LED lamps and featured with a light and handy design, has been recently proposed into the market. In this study we tested and compared the capture performances of this new trap with those of a classical light trap model under field conditions. From May to November 2013, a Laika trap and a classical light trap were placed biweekly in an area endemic for sand flies. A total of 256 sand fly specimens, belonging to 3 species (Sergentomyia minuta, Phlebotomus perniciosus, Phlebotomus neglectus) were collected during the study period. The Laika trap captured 126 phlebotomine sand flies: P. perniciosus (n=38); S. minuta (n=88), a similar number of specimens (130) and the same species were captured by classical light trap which collected also 3 specimens of P. neglectus. No significant differences in the capture efficiency at each day of trapping, neither in the number of species or in the sex of sand flies were observed. According to results of this study, the Laika trap may be a valid alternative to classical light trap models especially when handy design and low power consumption are key factors in field studies.

A Difference in Cutaneous Pigmentary Response to LED Versus Halogen Incandescent Visible Light: A Case Report from a Single Center, Investigational Clinical Trial Determining a Minimal Pigmentary Visible Light Dose.

BACKGROUND: While most of the attention regarding skin pigmentation has focused on the effects on ultraviolet radiation, the cutaneous effects of visible light (400 to 700nm) are rarely reported. In this report, we describe a case of painful erythema and induration that resulted from direct irradiation of UV-naïve skin with visible LED light in a patient with Fitzpatrick type II skin.

METHODS AND RESULTS: A 24-year-old healthy woman with Fitzpatrick type II skin presented to our department to participate in a clinical study. As part of the study, the subject underwent visible light irradiation with an LED and halogen incandescent visible light source. After 5 minutes of exposure, the patient complained of appreciable pain at the LED exposed site. Evaluation demonstrated erythema and mild induration. There were no subjective or objective findings at the halogen incandescent irradiated site, which received equivalent fluence (0.55 Watts / cm2). The study was halted as the subject was unable to tolerate the full duration of visible light irradiation.

CONCLUSION: This case illustrates the importance of recognizing the effects of visible light on skin. While the vast majority of investigational research has focused on ultraviolet light, the effects of visible light have been largely overlooked and must be taken into consideration, in all Fitzpatrick skin types.

J Drugs Dermatol. 2017;16(4):388-392.

Interaction of light quality and fertility on biomass, shoot pigmentation and xanthophyll cycle flux in Chinese kale.

BACKGROUND: Nutritionally important carotenoids in 21-day-old brassica microgreens increase following short and long-term exposure to narrow-band wavelengths from light-emitting diodes (LED). The present study aimed to measure the impact of: (1) fluorescent/incandescent light and different percentages of blue/red LED light and (2) different levels of nutrient fertility on biomass and pigment concentrations in 30-day-old 'Green Lance' Chinese kale (Brassica oleracea var. alboglabra). Kale plants were exposed to four light treatments and two fertility levels and were harvested 30 days after seeding and analyzed for nutritionally important shoot pigments. RESULTS: Kale under the fluorescent/incandescent light treatment had a significantly higher shoot fresh and dry mass. The shoot tissue concentrations of most pigment were significantly higher under blue/red LED light treatments. The higher fertility level resulted in higher concentrations for most pigments. Interestingly, the pool of xanthophyll cycle pigments and de-epoxidized xanthophylls was higher under all LED treatments. CONCLUSION: The results obtained in the present study support previous data demonstrating the stimulation of nutritionally important shoot tissue pigment concentrations following exposure to sole source blue/red LEDs compared to traditional lighting. Xanthophyll cycle flux was impacted by LEDs and this may support the role of zeaxanthin in blue light perception in leafy specialty crops. © 2016 Society of Chemical Industry.

Evaluation of light-emitting diodes as attractant for sandflies (Diptera: Psychodidae: Phlebotominae) in northeastern Brazil.

Hoover Pugedo light traps were modified for use with green and blue-light-emitting diodes to trap phlebotomine sandflies in northeastern Brazil. A total of 2,267 specimens belonging to eight genera and 15 species were sampled. The predominant species were Nyssomyia whitmani(34.41%) and Micropygomyia echinatopharynx(17.25%).The green LED trap prevailed over the blue and control lights; however, no statistically significant difference could be detected among the three light sources. Even without statistical significance, we suggest using LEDs as an attractant for the capture of sandflies because of several advantages over the conventional method with incandescent lamps.

Response of the sand fly Phlebotomuspapatasi to visual, physical and chemical attraction features in the field.

In this study, 27 CDC traps were modified with various attractive features and compared with a CDC trap with no light source or baits to evaluate the effects on attraction to Phlebotomus papatasi (Scopoli) north of the Dead Sea near Jericho. Attractive features included CO2, lights, colored trap bodies, heat, moisture, chemical lures and different combinations of the same. Traps were placed 20m apart and rotated from one trap location to the next after 24h trapping periods. The most significant attractive feature was CO2, which attracted more sand flies than any other feature evaluated. Ultraviolet light was the next most attractive feature, followed by incandescent light. When evaluated alone, black or white trap bodies, heat and moisture, all influenced trap catch but effects were greater when these attractive features were used together. The results of this study suggest that traps with CO2 and UV light could be used in batteries as control interventions if suitable CO2 sources become available.

Potential environmental impacts from the metals in incandescent, compact fluorescent lamp (CFL), and light-emitting diode (LED) bulbs.

Artificial lighting systems are transitioning from incandescent to compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs in response to the U.S. Energy Independence and Security Act and the EU Ecodesign Directive, which leads to energy savings and reduced greenhouse gas emissions. Although CFLs and LEDs are more energy-efficient than incandescent bulbs, they require more metal-containing components. There is uncertainty about the potential environmental impacts of these components and whether special provisions must be made for their disposal at the end of useful life. Therefore, the objective of this study is to analyze the resource depletion and toxicity potentials from the metals in incandescent, CFL, and LED bulbs to complement the development of sustainable energy policy. We assessed the potentials by examining whether the lighting products are to be categorized as hazardous waste under existing U.S. federal and California state regulations and by applying life cycle impact-based and hazard-based assessment methods (note that "life cycle impact-based method" does not mean a general life cycle assessment (LCA) but rather the elements in LCA used to quantify toxicity potentials). We discovered that both CFL and LED bulbs are categorized as hazardous, due to excessive levels of lead (Pb) leachability (132 and 44 mg/L, respectively; regulatory limit: 5) and the high contents of copper (111,000 and 31,600 mg/kg, respectively; limit: 2500), lead (3860 mg/kg for the CFL bulb; limit: 1000), and zinc (34,500 mg/kg for the CFL bulb; limit: 5000), while the incandescent bulb is not hazardous (note that the results for CFL bulbs excluded mercury vapor not captured during sample preparation). The CFLs and LEDs have higher resource depletion and toxicity potentials than the incandescent bulb due primarily to their high aluminum, copper, gold, lead, silver, and zinc. Comparing the bulbs on an equivalent quantity basis with respect to the expected lifetimes of the bulbs, the CFLs and LEDs have 3-26 and 2-3 times higher potential impacts than the incandescent bulb, respectively. We conclude that in addition to enhancing energy efficiency, conservation and sustainability policies should focus on the development of technologies that reduce the content of hazardous and rare metals in lighting products without compromising their performance and useful lifespan.

Analysis of energy saving lamps for use by photosensitive individuals.

Due to European legislation, the British government has begun the phase out of incandescent bulbs, to be replaced by energy-saving alternatives. The alternatives that are available on the market are Compact Fluorescent Lamps (CFL), Energy-Efficient Halogens (EEH) and Light Emitting Diodes (LED). Whilst previous research has shown that CFLs emit UVC, UVB and UVA, there is conflicting data available on whether double enveloped CFLs are a safer alternative to single enveloped CFLs for individuals suffering from photosensitivity. The emission spectra of 106 single enveloped CFLs and 65 double enveloped CFLs were measured. There were 17 different models of single enveloped CFLs, including lamps from 6 different manufacturers (ranging from 8-20 W) and 9 models of double enveloped CFLs from 6 different manufacturers (7-15 W). In addition, the emission spectra of 53 LEDs and 56 EEHs were also analysed. The LEDs consisted of 8 different models, from 3 manufacturers, spanning between 2.5 and 12 W. There were 11 models of EEH from 6 different manufacturers with wattages ranging from 28-70 W. In order to reduce sample bias, some bulbs were provided by the lighting industry federation and others were purchased randomly from local retailers. The results validate previous research in that considerable variation exists in the UV emitted from CFLs. This variation in UV levels is true, not only within different makes and models but also, surprisingly, within a box of 8 seemingly identical bulbs supplied by a single manufacturer. It was concluded that double enveloped CFLs do reduce the levels of UVC and UVB and therefore are a safer alternative for photosensitive individuals. However, as some double enveloped CFLs and EEHs do emit UVA at levels that provoke a reaction in the skin of UVA sensitive individuals, newly emerging LEDs that have minimal UV levels may provide a safer alternative.

Light-into-heat conversion in La2O3:Er(3+)-Yb3+ phosphor: an incandescent emission.

Low-power-threshold cw laser-induced incandescence (CWLII) has been observed in La(2)O(3):Er(3+)-Yb(3+) phosphor on excitation by a 976 nm IR laser. It is suggested that incandescence originates from the extensive heating induced by the nonradiative processes taking place following the laser excitation. Other mechanisms for similar observations have also been suggested in the literature and have been discussed with the present observations. The estimated temperature for the CWLII approaches around 2650 K, and this seems to provide an effective way to rapidly attain high temperature in nano/microvolumes of phosphor. The phosphor exhibited efficient upconversion, and the ratio of the (2)H(11/2)→(4)I(15/2) and (4)S(3/2)→(4)I(15/2) band intensities of Er(3+) permits measurement of the temperature rise, from a distance.

Are emissions of black carbon from gasoline vehicles underestimated? Insights from near and on-road measurements.

Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO(2) measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies.

Spectral transmittance of intraocular lenses under natural and artificial illumination: criteria analysis for choosing a suitable filter.

PURPOSE: To compare the spectral transmission of different intraocular lenses (IOLs) with either ultraviolet (UV) or blue-light filters, and to analyze the performance of these filters with artificial light sources as well as sunlight. DESIGN: Experimental study. METHODS: The spectral transmission curve of 10 IOLs was measured using a PerkinElmer Lambda 800 UV/VIS spectrometer (Waltham, MA). Different filtering simulations were performed using the D65 standard illuminant as daylight and standard incandescent lamp and fluorescent bulb illuminants. MAIN OUTCOMES MEASURES: Spectral transmittance of the IOLs. RESULTS: All the IOLs studied provide good UVC (200-280 nm) and UVB (280-315 nm) protection, except for one that presented an appreciable window at 270 nm. Nevertheless, both natural and artificial sources have practically no emission under 300 nm. In the UVA (315-380 nm) range the curves of the different IOLs manifested different degrees of absorption. CONCLUSIONS: Not all the UV filters incorporated in different IOLs protect equally. The filters that provide greater photoprotection against UV radiation, even blue light, are yellow and orange. Then, yellow and orange IOL filters may be best suited for cases requiring special retinal protection. The filters that favor better photoreception of visible light (380-780 nm) are those that transmit this radiation close to 100%. Artificial illumination practically does not emit in the UV range, but its levels of illumination are very low when compared with solar light. A possible balance between photoprotection and photoreception could be a sharp cutoff filter with the cutoff wavelength near 400 nm and a maximum transmittance around 100%.

Visual performance for trip hazard detection when using incandescent and led miner cap lamps.

INTRODUCTION: Accident data for 2003-2007 indicate that slip, trip, and falls (STFs) are the second leading accident class (17.8%, n=2,441) of lost-time injuries in underground mining. Proper lighting plays a critical role in enabling miners to detect STF hazards in this environment. Often, the only lighting available to the miner is from a cap lamp worn on the miner's helmet. The focus of this research was to determine if the spectral content of light from light-emitting diode (LED) cap lamps enabled visual performance improvements for the detection of tripping hazards as compared to incandescent cap lamps that are traditionally used in underground mining. A secondary objective was to determine the effects of aging on visual performance. METHOD: The visual performance of 30 subjects was quantified by measuring each subject's speed and accuracy in detecting objects positioned on the floor both in the near field, at 1.83 meters, and far field, at 3.66 meters. Near field objects were positioned at 0 degrees and +/-20 degrees off axis, while far field objects were positioned at 0 degrees and +/-10 degrees off axis. Three age groups were designated: group A consisted of subjects 18 to 25 years old, group B consisted of subjects 40 to 50 years old, and group C consisted of subjects 51 years and older. RESULTS: Results of the visual performance comparison for a commercially available LED, a prototype LED, and an incandescent cap lamp indicate that the location of objects on the floor, the type of cap lamp used, and subject age all had significant influences on the time required to identify potential trip hazards. The LED-based cap lamps enabled detection times that were an average of 0.96 seconds faster compared to the incandescent cap lamp. Use of the LED cap lamps resulted in average detection times that were about 13.6% faster than those recorded for the incandescent cap lamp. The visual performance differences between the commercially available LED and prototype LED cap lamp were not statistically significant. IMPACT ON INDUSTRY: It can be inferred from this data that the spectral content from LED-based cap lamps could enable significant visual performance improvements for miners in the detection of trip hazards.

Ultraviolet light output of compact fluorescent lamps: comparison to conventional incandescent and halogen residential lighting sources.

Patients with photosensitive dermatologic and systemic diseases often question the ultraviolet light (UVL) output of household lighting sources. Such individuals have increasing concern about potential UVL exposure from energy-efficient compact fluorescent lamps (CFL), as little data have been presented concerning their UVL output. The objective was to compare, via pilot study, the levels of ultraviolet A (UVA) and ultraviolet B (UVB) leak between residential lighting sources. Equivalent wattage CFL, incandescent and halogen bulbs were purchased from local retailers in Oklahoma City, Oklahoma, USA. The UVA and UVB outputs of these sources were measured under controlled conditions at 10, 25, 50, 100 and 150 cm away from the light source using an IL-1700 research radiometer equipped with UVA and UVB detectors. Negligible UVB and UVA was detected at 100 and 150 cm. Therefore, data were analysed from measurements at 10, 25 and 50 cm only. The results demonstrated UVA leak highest from incandescent and halogen bulbs, and UVB leak highest from CFL. The overall UVA/UVB leak was lowest from CFL shielded during the manufacturing process. In conclusion, patients with photosensitivity have choices depending on their relative risk from different UVL wavelength spectra. UVB exposure risk may be reduced the greatest by utilising CFL with manufacturer-provided shields.

The risk of ultraviolet radiation exposure from indoor lamps in lupus erythematosus.

It is well known that ultraviolet radiation can exacerbate skin disease in patients with lupus erythematosus. While many patients are advised to avoid sunlight and artificial tanning, it is not clear how best to counsel patients regarding the use of indoor lamps. Indeed, many of the light bulbs commonly used in the home and workplace emit low-dose ultraviolet radiation. The irradiance is considerably lower than that of the sun, however the exposure time can last for hours and is typically repeated on a daily basis. Therefore, it is possible that this chronic exposure could ultimately result in a significant accumulation of damage.

Occurrence of refractive errors among students who before the age of two grew up under the influence of light emitted by incandescent or fluorescent lamps.

PURPOSE: The aim of the study was to determine whether the development of refractive errors could be associated with exposure to light emitted by incandescent or fluorescent lamps. MATERIAL AND METHODS: 3636 students were examined (1638 boys and 1998 girls, aged 6-18 years, mean age 12.1, SD 3.4). The examination included skiascopy with cycloplegia. Myopia was defined as refractive error < or = -0.5 D, hyperopia as refractive error > or = +1.5 D, astigmatism as refractive error > 0.5 DC. Anisometropia was diagnosed when the difference in the refraction of both eyes was > 1.0 D. The parents of all the students examined completed a questionnaire on the child's light exposure before the age oftwo. Data were analyzed statistically with the chi2 test. P values of less than 0.05 were considered statistically significant. RESULTS: It was observed that sleeping until the age of two in a room with a light turned on is associated with an increase in the occurrence of anisometropia (p < 0.02) as well as with a reduction in the prevalence of emmetropia (p < 0.05). It was also found that light emitted by fluorescent lamps leads to more frequent occurrence of astigmatism (p < 0.01).