Using Light in Environmental Testing or Forensic Building Investigations

LIGHT, GUIDE to FORENSIC USE - A guide to effective use of light levels, direction, color, frequency & methods for forensic investigation
LIGHT AIM FINDS MOLD - separate article
LIGHT, flashlight to find mold - separate article
Questions & Answers about the use of light, lighting, light levels, reflected light, transmitted light, polarized light, UV light or black light, and light color or wavelengths in forensic, building and microscopic investigations
References

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How to use light in building forensic or environmental investigation work in the field and in the test laboratory. This article describes the optimum use of light & types of lighting in building & forensic investigations. We describe examples and provide links to detailed information about how the angle, color, frequency, intensity, and other aspects of lighting can make it either possible or impossible to detect various particles and substances.

Optimum Adjustments & Uses of Infra Red, Visible Light, & UV Light in Building, Environmental & Forensic Investigation

The range of "light" illumination, colors, and energy levels useful in building & environmental investigations includes both the entire visual spectrum and also sensors in the infrared and ultraviolet ends of the spectrum that have special applications. Here we describe the range of light and light uses in forensic work.

Airborne debris indoors (C) Daniel Friedman

As our pair of photographs above illustrate, careful use of lighting can make airborne particles quite apparent. (Discussed at INDOOR AIR QUALITY IMPROVEMENT GUIDE).

A Catalog of Effective Use of Light in Building Investigations, Environmental Testing, & Forensic Investigations

Asbestos Under the Microscope - using polarized light microscopy and darkfield microscopy for asbestos identification. McCrone illustrated that tremolite asbestos (as well as some other forms of asbestos) occur in both fibrous and non-fibrous form. Comparing the photo at below left (tremolite in fibrous form) by McCrone to ours (below right) that shows fewer small non-fibrous particles, but a clear bundle of ultra-fine sub-micron (in width) fibers.

Photograph of - tremolite asbestos, asbestiform tremolite, collected from asbestos slab ceiling insulation

Photograph of LARGER IMAGE - tremolite asbestos, non-asbestiform tremolite, collected from the same sample of asbestos slab ceiling insulation

ASBESTOS FLOOR TILE LAB PROCEDURES provides further examples of polarized light microscopy

BLOOD in ART WORKS, TESTING FOR fluorescent light & luminol quick tests for blood require additional steps to confirm human blood

CARPET STAIN DIAGNOSIS - includes of course stains from mold, pet urine, or worse. Also see CARPET & other STAIN TESTS and CARPET TEST PROCEDURE. And see URINE / ANIMAL ODORS IN BUILDINGS .

Color Temperature Bulb Comparisons is a helpful article for understanding the forensic use of light in building investigations. We illustrate how some objects can appear as very different colors under differing light sources.

DUCT SYSTEM & DUCT DEFECTS - how to find, clean up or remove, or prevent contamination problems and indoor air quality problems in duct systems: asbestos, fiberglass, flooding, mold, water, and other duct contaminants

EFFLORESCENCE, Salts & White / Brown Deposits - don't confuse effloresence with fluoresence discussed in our UV light articles (below).

GAS BURNER Flame & Noise Defects - observing flame color indicates level of combustion & combustion air defects - illustrated in our photo at left. More details are at FLAME COLOR, BLUE vs YELLOW COMBUSTION and GAS BURNER Flame & Noise Defects.

Gas Lighting Pipes & Fixtures - detection of antique gas piping that may still be "live", a fire & gas hazard in buildings

GREENHOUSE / SUNSPACE GLARE illustrates how too much light or light that is too direct can actually be blinding

INDOOR AIR QUALITY IMPROVEMENT GUIDE- using light and angle of light correctly can make it easier to spot settled dust on building surfaces, aiding in sample collection, as well as providing more subjective spotting of airborne particulate debris as we illustrated in the pair of photos earlier on this page.

THERMOGRAPHY IR Infra Red & THERMAL SCANNERS - Thermal scanners or infra red IR scanners and thermography cameras ease finding points of heat loss or air infiltration in buildings. See HEAT LOSS DETECTION TOOLS and also ALUMINUM WIRING HAZARDS & REPAIRS where we provide an example of aluminum wiring overheating.

Lab Identification of Fiberglass - includes a discussion of the importance of the use of proper refractive index liquid & polarized light for identification of these materials.

Laser light inspection methods - [in process] [20]

direct lighting hides problematic light colored mold colony on this wainscot paneling

LIGHT AIM FINDS MOLD - how to use oblique lighting to find mold contamination or other surface dust contaminants in buildings

LIGHT, flashlight to find mold - know how to aim a flashlight during building investigations: oblique vs. direct reflected light

Our photo illustrates the appearance of light colored mold contamination on a building wall - a contaminant that was impossible to see with the naked eye unless light was aimed on an oblique angle.

LIGHT, GUIDE to FORENSIC USE - a guide to effective use of light levels, direction, color, frequency & methods for forensic investigation

LIGHTING, EXTERIOR GUIDE - recomended types, ambient levels, illumination levels for various tasks & building areas, outdoors

LIGHTING, INTERIOR GUIDE - recomended types, ambient levels, illumination levels for various tasks & building areas, indoors

Lab microscope and camera (C) Daniel Friedman

MICROSCOPE TECHNIQUES for the LAB: use of transmitted light, reflected light, polarized light, darkfield, refractive index liquids, & the POLAM tilting color filter stage for variation in wavelength of transmitted light for particle identification. The POLAM filter stage allows particle identification without resorting to a full set of refractive index liquids. Top lighting allows us to quickly distinguish between certain very round fungal spores and spray paint droplets of the same size range.

Polarized light combined with measures angular rotation through the polarized field allows very accurate fiber and other particle identification.

OPTIMUM INDOOR AIR FILTERS - use of UV light in duct work & air handlers to retard biological contaminant growth

PAINT ANALYSIS, DIAGNOSTIC USES provides examples of use of microscopy and reflected light microscopy or top lighting to examine the causes of paint failures and to detect paint particles in air, dust or surface samples.

Also see PAINT LAB SAMPLE PREPARATION.

Polilight and similar devices can provide a light source of variable wavelength for widely applicable forensic uses. [23] This approach is similar to that used our Russian-designed POLAM microscope described just above.

SEPTIC DYE TEST PROCEDURE - using a fluorescein septic dye, usually green (photo at left) or red can detect even very dilute presence of tracer dye in septic tank or drainfield failures, leaks, and contamination of surfaces or wateways

STAIN DIAGNOSIS on BUILDING EXTERIORS and STAIN DIAGNOSIS on BUILDING INTERIORS can benefit from use of ultraviolet light for detection of URINE / ANIMAL ODORS IN BUILDINGS - also see

Dog urine stains indoors (C) Daniel Friedman

UV LIGHT BLACK LIGHT USES - for detection of human & animal bodily fluids, urine, blood, and many other fluorescing materials

UV -ULTRAVIOLET LIGHT TREATMENT - partial purification of water by killing bacteria

UV WATER DISINFECTION, PORTABLE

UV light for air ducts (C) Daniel Friedman

UV light on well and pump system (C) Daniel Friedman

UV light treatment in the duct system or air handler (photo above left) is available for HVAC systems and may be slightly helpful for areas where occupants are at extreme medical risk. See OPTIMUM INDOOR AIR FILTERS. At above right, a UV light is installed on a private well water system. See UV -ULTRAVIOLET LIGHT TREATMENT - partial purification of water by UV to kill bacteria. Other treatment methods may be needed if Giardia is present in the water supply.

Proper angling of lighting or a flashlight allows much more effective discovery of settled dust on building surfaces (photo, below left). In the forensic lab a study of this dust found typical fabric fibers, skin cells, starch granules. Discussed at Lab Identification of Fiberglass.

fibers not fiberglass (C) Daniel Friedman

Without use of a mounting liquid of the proper refractive index range and proper microscope adjustment it can be difficult or even impossible to detect small fiberglass fragments in air and dust samples. Use of polarized light with proper mountants can also quickly confirm that fibers found in an environmental sample are fiberglass. At below left the concoidal fractures on the ends of fibers is confirming evidence of that this is a glass or fiberglass fiber. At below right, the presence of resin on the fiber is also indicative. Also see FIBERGLASS PARTICLE CONTAMINATION TEST.

$photo of concoidal end fracture on fiberglass fragment$

photo of resin binder on fiberglass insulation fragments

VISUAL PERCEPTION ERRORS - The Nature of Vision - Inspecting Complex Systems, Why We See or Do Not See Things We Are Looking For - Or Should Be Looking For

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Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

[1] About.com - Chemistry http://chemistry.about.com/cs/howthingswork/f/blblacklight.htm
[2] Several light & forensic suppliers, e.g. Doje's (see our article on checking for blood in art work by Frida Kahlo at BLOOD in ART WORKS, TESTING FOR)
- Judy and Don Doje, Doje's Forensic Supplies, P.O. Box 500, Ocoee, FL 34761
[2a] Ulrik Runeberg, Conservador, Museo de Arte Contemporaneo de Puerto Rico, San Juan, Puerto Rico
[3] U. Illinois Dept of Physics, http://van.physics.illinois.edu/qa/listing.php?id=1913
[4] Glow Paint Industries, an Australian company ( 07-5483-9181) http://www.glowinthedark.net.au/ claims to provide the world's longest list of products that glow in the dark, listing toys, party supplies, home improvementproduts, rereation & sport products, paints, and more.
[5] FEIT ELECTRIC COMPANY, INC. 4901 Gregg Road Pico Rivera, CA 90660-2108, Tel: (800) 543-FEIT (3348), website: http://www.feit.com/ web search 5/14/2012
[6] "What You Need to Know about UL 1598, 3rd Edition", Intertek, Tel: 800-967-5352, USA, offices in the Americas, Germany, Sweden, Asia Pacific, Italy, UK. Website: www.intertek.com/lighting, web search 5/14/12 [Copy on file as UL-1598-White-Paper.pdf]
[7] "ANSI Coded Light Bulbs", Bulbstock.com, web search 5/14/12, original source: http://www.bulbstock.com/AnsiCodedLightBulbs.html
[8] ANSI American National Standards Institute, website: www.ansi.org [Don't expect to easily find anything you need to know at the ANSI website - Ed.] Example: [http://www.ansi.org/news_publications/news_story.aspx?menuid=7&articleid=2628]
The National Electrical Manufacturers Association (NEMA), on behalf of the American National Standard Lighting Group (ANSLG), has published ANSI/ANSLG C78.81-2010, Electric Lamps - Double-Capped Fluorescent Lamps - Dimensional and Electrical Characteristics. The recently published standard sets forth the physical and electrical characteristics of the principal types of fluorescent lamps intended for application on conventional line frequency circuits and electronic high-frequency circuits.
ANSI/ANSLG C78.81-2010 revises a 2005 edition and provides specifications for the lamp itself, the interactive features of the lamp, and the lamp ballast, including conventional systems relying on auxiliary support from external ballasts. In addition, three new fluorescent lamp data sheets are included: 25-Watt, 48-Inch T8, High-Frequency Fluorescent Lamp; 28-Watt, 48-Inch T8, High-Frequency Fluorescent Lamp; and 30-Watt, 48-Inch T8, High-Frequency Fluorescent Lamp. Only double-based lamps of the regular linear shape are included in the standard; single-based compact, circular, square, and U-shaped lamps are found in NEMA/ANSI C78.901:2005, For electric lamps single base fluorescent lamps - dimensional and electrical characteristics.
NEMA, an ANSI organizational member and accredited standards developer, is a membership organization of manufacturers of products used in the generation, transmission, distribution, control, and end-use of electricity used in utility, medical imaging, industrial, commercial, institutional and residential applications.
[9] Wikipedia provided background information about some topics discussed at this website provided this citation is also found in the same article along with a " retrieved on" date. NOTE: because Wikipedia entries are fluid and can be amended in real time, we cite the retrieval date of Wikipedia citations and we do not assert that the information found there is necessarily authoritative.
Entry on color temperature, 5/14/2012, original source: http://en.wikipedia.org/wiki/Color_temperature
Entry on lumen, 5/14/12, original source: http://en.wikipedia.org/wiki/Lumen_(unit)
Entry on Wien's displacement law, 5/14/12, original source http://en.wikipedia.org/wiki/Wien's_displacement_law
[10] "Notes on LEDs & Kelvin Color Scale", Autolumination, website: autolumination.com, web search 5/14/12, original source: http://autolumination.com/colors.htm [copy on file as LED_Notes_AutoIll.pdf]
[11] Light Booth, Type LBM-B", Mathis. Mathis is headquartered in Brasil (Website: http://www.mathis.com.br/, Email: mathis@mathis.com.br) with offices in Switzerland & the USA and other countries. Werner Mathis AG Rütisbergstrasse 3 CH-8156 Oberhasli/Zürich, Switzerland Telefon 41(0)44-852 5050 Telefax 41(0)44-850 6707 E-Mail info@mathisag.com Homepage www.mathisag.com, other worldwide locations: Werner Mathis U.S.A. Inc. 2260 HWY 49 N.E./P.O. Box 1626 Concord N.C. 28026, U.S.A. Phone: 1-704-786-6157 Fax: 1-704-786-6159 E-mail: usa@mathisag.com, Mathis (India) PVT. LTD. 203, Swastic plaza Pokhran Road No. 2, Thane 400 601, India Phone: +91 22 2585 4304 E-mail: india@mathisag.com, and Mathis (India) PVT. LTD. 203, Swastic plaza Pokhran Road No. 2, Thane 400 601, India Phone: +91 22 2585 4304 E-mail: india@mathisag.com.
Mathis provides a lighting boot for visual assessment and comparison of colors, use to compare color variations and metamerism on samples. The light booth provides four or five standardized light sources (daylight -D65, fluorescent -TL84, incandescent - A home light color temp. of 2,856, ultravoilet - UV to evaluate optical brightener or fluorescent dyes, and a 5th optional lamp providing D50-artificial daylight 5,000K, D75-artificial daylight 7,500K, H-horizon light 2,300K, CWF- store light, cool fluorescent 4,150K.) Web search 5/14/12, original source: http://www.mathis.com.br/arquivos/PDF/ing/LBM-ing.pdf, [copy on file as Mathis_Light_Booth_LBM-ing.pdf]
[12] A. J. Swerdlow, J. S. English, R. M. MacKie, C. J. O'Doherty, J. A. Hunter, J. Clark, and D. J. Hole, "Fluorescent lights, ultraviolet lamps, and risk of cutaneous melanoma.", BMJ v.297(6649); Sep 10, 1988 PMC1834365 (This article has been corrected. See BMJ. 1988 November 05; 297(6657): 1172.) -
Abstract: Exposure to solar radiation is increasingly being associated with a risk of cutaneous melanoma, and some risk has also been attributed to exposure to fluorescent lights. The risk of cutaneous melanoma associated with exposure to some sources of artificial ultraviolet radiation was examined in a case-control study in a Scottish population with fairly low exposure to natural ultraviolet radiation. The risk was not significantly or consistently raised for exposure to fluorescent lights at home or at work. The use of ultraviolet lamps and sunbeds, however, was associated with a significantly increased risk (relative risk = 2.9; 95% confidence interval 1.3 to 6.4), and the risk was significantly related to duration of use. The risk was particularly raised among people who have first used [corrected] ultraviolet beds or lamps more than [corrected] five years before presentation (relative risk = 9.1; 95% confidence intervals 2.0-40.6), in whom it was significantly related to cumulative hours of exposure. The risks associated with exposure to ultraviolet lamps and sunbeds remained significant after adjustment for other risk factors for melanoma.
[13] Hug, William F., "Inspection/Detection System with a light module for use in fornsic applications", United States Patent No. 4,933,816, Jun 21 1990.
[14] Pounds, C. A., Grigg, R., and Mongkolaussavaratana, T., "The Use of 1,8- Diazafluoren-9-one (DFO) for the Fluorescent Detection of Latent Fingerprints on Paper. A Preliminary Evaluation," Journal of Forensic Sciences, JFSCA, Vol 35, No. 1, Jan. 1990, pp. 169-175.
- Abstract: The use of a new amino acid reagent 1,8-diazafluoren-9-one (DFO), which produces a highly fluorescent species with latent fingerprints on paper, is described. Spectral characteristics of the fluorescent fingerprint show excitation (kox approximately 470 nm) and emission (ko~ approximately 570 nm) maxima in the visible'part of the spectrum. Some printing inks fluoresce under these conditions and would therefore hinder fingerprint detection, but optical brighteners present in paper do not interfere. Fluorescent fingerprints visualized by DFO revealed more fingerprint detail than ninhydrin, the standard method for such surfaces.
retrieved 07/24/2012 original source http://library-resources.cqu.edu.au/JFS/PDF/vol_35/iss_1/JFS351900169.pdf [ copy on file as /Inspetion Methodology/UV_Fingerprint_Detect.pdf ]
[16] Barsley, Robert E. D.D.S., J.D.; West, Michael H. D.D.S.; Fair, John A. M.S., R.P.S, "Forensic Photography: Ultraviolet Imaging of Wounds on Skin", The American Journal of Forensic Medicine and Pathology, December 1990 - Volume 11 - Issue 4, Abstract: The use of ultraviolet light (UVL) to study and document patterned injuries on human skin has opened a new frontier for law enforcement. This article discusses the photographic techniques involved in reflective and fluorescent UVL. Documentation of skin wounds via still photography and dynamic video photographic techniques, which utilize various methods of UV illumination, are covered. Techniques important for courtroom presentation of evidence gathered from lacerations, contusions, abrasions, and bite marks are presented through case studies and controlled experiments. Such injuries are common sequelae in the crimes of child abuse, rape, and assault.
[17] Karen A. Santucci, MD*, David G. Nelson, MD*, Kemedy K. McQuillen, MD‡, Susan J. Duffy, MD*, James G. Linakis, PhD, MD*, "Wood's Lamp Utility in the Identification of Semen", Pediatrics Vol. 104 No. 6 December 1, 1999 pp. 1342 -1344 (doi: 10.1542/peds.104.6.1342), Abstract Background. The accurate detection of semen is critical to forensic, medical, and legal personnel. The Wood's lamp (WL) emits ultraviolet light (UVL) and has been identified as useful in rape evaluations because it is purported to cause semen to fluoresce. This study was intended to determine if semen can be distinguished from other products by WL analysis. Methods. Investigators reviewed the previous training and frequency of use of the WL by emergency medicine and pediatric emergency medicine physicians at 2 medical centers. The participants were asked to use a WL to distinguish between a semen sample (<6 hours old) and 13 commonly used products. Next, 29 semen samples were collected and evaluated under high-power microscopy and under UVL. Results. A total of 41 physicians participated in the study (68% male). The number of years practicing in an emergency setting spanned from .3 to 25 years with a mean of 7.1 years. A total of 51% of participants trained in emergency medicine, 23% in pediatrics and pediatric emergency medicine. A total of 22% reported formal training in the collection of forensic evidence. A total of 62% of the physicians believed they have identified semen in the past; one third felt they could differentiate semen from other products under UVL. None of the 41 physicians were able to differentiate semen from other products using a WL. Moreover, the semen samples used for the study did not fluoresce under WL analysis. None of the 29 semen samples fluoresced whether wet or dry. The medicaments most commonly mistaken for semen were A&D ointment (Cardinal Health, Inc, Dublin, OH), Surgilube (Division of Atlanta, Inc, Melville, NY), Barrier cream (Carrington Laboratories, Inc, Irving, TX), and bacitracin (Division of Atlanta, Inc, Melville, NY). Conclusions. Participating physicians were unable to distinguish between semen and other common products, using the WL. Although the WL has been purported to be a useful tool as a screening device for the detection of seminal stains, the investigators have found it to be unreliable. Semen, previously reported to fluoresce under WL analysis, does not appear to do so. The correct identification of semen may be complicated by the presence of previously existing ointments and creams, some of which may be iatrogenically introduced (ie, Surgilube).
[18] Dr. Bruce Budowle1,*, F. Samuel Baechtel, Catherine T. Comey, Alan M. Giusti, Leonard Klevan, "Simple protocols for typing forensic biological evidence: Chemiluminescent detection for human DNA quantitation and restriction fragment length polymorphism (RELP) analyses and manual typing of polymerase chain reaction (PCR) amplified polymorphisms", ELECTROPHORESIS Volume 16, Issue 1, pages 1559–1567, 1995,
Abstract Methods for identity testing are described that enable extraction of DNA from biological samples, determination of the quantity of human DNA, and genetic analyses of the materials using restriction fragment length polymorphism (RFLP) typing and/or amplified fragment length polymorphism (AMP-FLP) typing of PCR products. The salient features of the procedures are simplicity, manual typing, nonradioactive chemiluminescent assays or silver staining for detection, and low cost. Most application-oriented laboratories involved in forensic and/or paternity testing should be able to implement these procedures.
[19] C.Y. Wenemail address , J.K. Chen, "Multi-resolution image fusion technique and its application to forensic science", Forensic Science International Volume 140, Issue 2 , Pages 217-232, 10 March 2004,
Abstract Image fusion is a process of combining two or more images into an image. It can extract features from source images, and provide more information than one image can. Multi-resolution analysis plays an important role in image processing, it provides a technique to decompose an image and extract information from coarse to fine scales. In some practical forensic examinations (such as the cartridge image check), we cannot obtain all information from just one image; on the contrary, we need information from images with difference light sources (or light ways). In this paper, we apply an image fusion method based on multi-resolution analysis to forensic science. Synthetic and real images (such as images from closed-up photography and flash photography) are used to show the capability of the multi-resolution image fusion technique.
[20] Hug, William F. et al., "Inspection / Detection System with a laser module for use in forensic applications", United States Patet No. 5,072,338, 10 Dec. 1991 [also see Hug's UV light carrying system - ref 13 above].
[21] Jacob Wawryk, Morris Odell, "Fluorescent identification of biological and other stains on skin by the use of alternative light sources" Journal of Clinical Forensic Medicine Volume 12, Issue 6 , Pages 296-301, December 2005,
Abstract The detection of body fluids in cases of sexual assault or abuse is important for purposes of evidence collection and DNA testing. In cases where semen is deposited on skin, a method for detection of semen may be a valuable aid to evidence collection [Gabby T, Winkleby M, Boyce T, Fisher D, Lancaster A, Sensabaugh G. Sexual abuse of children. The detection of semen on skin. AJCD 1992; 146:700–703]. Semen is known to fluoresce when exposed to light of certain wavelengths. For this study, we placed various body fluids, as well as lubricants and moisturizers on the forearms of volunteers. The areas were illuminated using Alternative Light Sources (ALS) with peak wavelengths of between 370 and 500nm for examination soon after deposition, and again after 24h. No fluorescence was visible from any of the substances in the majority of volunteers examined. In a few subjects, semen and urine were found to fluoresce faintly under the more powerful lights. In these cases, the quality of fluorescence provided by urine and semen was noticeably different. For comparison, semen was applied to cloth, and fluoresced well at the expected wavelengths. While ALS is useful for identification of stains on clothing, its use in detecting stains on skin is currently very limited.
[22] Milutin Stoilovic, "Detection of semen and blood stains using polilight as a light source", Forensic Science International Volume 51, Issue 2, October 1991, Pages 289–296,
Abstract Photoluminescence spectra of dry untreated semen have been measured and a suggested method for rapid detection of untreated semen stains is derived from these measurements. The method is presented in the form of a flow chart to cover most crime scene situations. The absorption spectrum of dry untreated blood has also been measured and a suggested method for enhancement and photography of blood stains is derived from this measurement. The method is presented in the form of a flow chart. Both methods are based on the use of a high intensity light source such as the Polilight.
[23] Polilight, BVDA International b.v. Postbus 2323 2002 CH HAARLEM - The Netherlands, Email: info.usa@bvda.com, web search 07/24/12, original source: http://www.bvda.com/EN/sect16/en_16_1b.html -
Sales literature quote " The Polilight 400 is a robust light source based on a 400-watt metal halide arc lamp. This type of lamp delivers UV and visible light. The output is not as high as that of a xenon arc lamp of comparable wattage would deliver, especially in the UV and blue region, but the light output is still high.... The high quality filters (made by Rofin) that provide the desired output band (color light) are mounted on a filter wheel. The motorised filter wheel is operated with buttons on the front panel of the unit or using the hand held remote control (on a 3 m-long cable connected through a RS232 port on the rear panel). Filter change is stepwise: choosing a higher or lower wavelength as desired. The selected wavelength (which in the visible region has a bandwidth of about 50 nm) is displayed on a 3 figure display. Fine tuning of the bandwidth or intensity control of the light is not available. "

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