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"Karauli District is a district of Rajasthan state in western India. The town of Karauli is the district headquarters. Karauli District comes under Bharatpur Divisional Commissionerate. Karauli is famous for popular red-stone. The population of the district is 1,458,248 (2011 census), indicating a population density is 264 persons per km2. Geography and location The district of Karauli encompasses an area of 5043 km2. It is bordered by Dholpur District to the east; by Bharatpur District to the north-east; by Dausa District to the north; and by Sawai Madhopur District to the west. The Chambal River forms the south-eastern boundary of the district, 5 km from Mandrayal across which lies the state of Madhya Pradesh. While almost the entire district is covered by hills and ravines, there are no lofty peaks, the highest having an elevation of less than 1400 feet above sea level. Good grade stone and some iron ore comprise the mineral resources of the area. Topography Karauli's natural environment includes the Vindhyanchal and Aravali mountains. The district has plain, high and low and hilly parts. The plains are fertile and clay is lightweight and sandy. There are many rivers in the district. Annual rainfall is 668.86 mm, about 35 days in a year. Maximum temperature is 49 °C in May and 2 °C in January. History Availability of minerals Sandstone, Missionary Stone, Silica sand, Soapstone, White clay are the major Minerals found in this district. About 200 small units are using sandstone for cutting & polishing of stones to be used in building making. How to reach Karauli Karauli Location- Karauli city is located in the Karauli district in the east of Rajasthan state in western India. Karauli is situated at 169 Kilometres from Gwalior, 114 kilometres west from Agra and 158 kilometres from the city of Jaipur. It has an average elevation of 275 metres (902 ft). Tourist places *Kaila Devi Temple is a Hindu temple situated 23 km from Karauli and 37 km from Gangapur. It is located on the banks of the Kalisil river, a tributary of the Banas River in the hills of Trikut, 2 km to the north-west of Kaila village. The temple is dedicated to the tutelary deity, goddess Kaila Devi, of the erstwhile princely Jadaun Rajput rulers of the Karauli state. It is a marble structure with a large courtyard of a checkered floor. In one place are a number of red flags planted by devotees. *Madan Mohan Temple is a form of the Hindu god Krishna. Krishna is celebrated as Madan Mohan, who mesmerises everyone. His consort, Radha is glorified as Madan Mohan's Mohini, the mesmeriser of the mesmeriser for spiritual aspirants. Radha is known as the mediator without whom access to Krishna is not possible. *Mehandipur Balaji Temple is a mandir in the Indian state of Rajasthan dedicated to the Hindu God Hanuman. The name Balaji is applied to Sri Hanuman in several parts of India because the childhood (Bala in Hindi or Sanskrit) form of the Lord is especially celebrated there. It is important to note that the temple is not dedicated to Balaji another name for Krishna. Unlike similar religious sites it is located in a town rather than the countryside. Its reputation for ritualistic healing and exorcism of evil spirits attracts many pilgrims from Rajasthan and elsewhere. *Shri Mahavir Ji Temple is in Hindaun City. Earlier known as Chandanpur, this small village became famous as a Jain religious site after an ancient idol of Mahaveer was excavated from its soil several hundred years ago. It was then renamed as Shri Mahaveer Ji This idol was excavated over 200 years ago from the same spot, after which the temple was constructed. Thousands of worshipers flock from across India to catch a glimpse of this statue. *Nakkash Ki Devi - Gomti Dham Temple is in Hindaun City. It is a Hindu Devi Temple of Durga Mata and Gomti Dham is a Temple and Vatika(ashram) of Gomti Dass Ji Maharaj. *Mandrayal, 40 km from the district headquarters is Mndrayl Durg. The year 1327 was dominated by Arjun Dev about the ruler of Karauli. The Trinity Baradari temple, located in the middle of the court, and is worth a visit Bala Durg. Rhugat in Chambal River flows nearby waterfall. Forest The forest covers an area of 172,459 hectares in 2010–11, which is about 30% of total geographical area of the district's 504,301 hectares. As per the records of 2011–12. total 895.2 mm rainfall was recorded against 565 mm average rainfall. Administrative setup Karauli City is the district headquarters of Karauli district, which is divided into 8 tehsils, 6 subdivisions, 223 panchayats, 881 villages, 6 panchayat samiti and 2 Nagar Parishad, 1 Nagarpalika. =Subdivisions in Karauli District= * Hindaun Subdivision * Karauli * Todabhim * Nadoti * Sapotra * mandrail * suroth * Masalpur =Panchayat Samiti in Karauli= * Hindaun Panchayat Samiti * Karauli * Todabhim * Nadoti * Sapotra * mandrayal * Masalpur =Nagar- Parishad & Palika= * Hindaun City * Karauli * Todabhim Weather The climatic condition of Karauli district is throughout the year sunny temperature ranging between high 35 °C and low 23 °C. The humidity of this region ranges from 31 to 35% with a dew point of 11° to 15°. The winds speed is NW 11–15 km/h. The chance of precipitation may be 30% to 40%. During the rainy season the village gets scattered showers. This region is termed to be dry climate area of subtropical region. There is also distinct winter and long summer season. The recorded highest temperature is 49 °C during May–June and lowest temperature is 20 °C during January. The average rainfall recorded in this district is 880 mm. The monsoon season falls in July to September. Settlements *Hindaun *Karoli ke samacharRoli ki vid *Todabhim *Nadauti *Sapotara Temples There are four major temples in Karauli district, hence they are called Char Dham of Karauli: *Kaila Devi temple, Kaila devi, Karauli * Krishna temple, Karauli (Madan Mohan) * Mehandipur Balaji Temple, Todabhim *Anjani Mata Temple * Nanded Bhumia Temple, Tulsipura, Karauli =Hindaun Block= * Shri Mahavirji Temple, Hindaun City * Narsinghji Temple, Hindaun City * Nakkash Ki Devi - Gomti Dham, Hindaun City * Kyarda Hanumanji Temple, Hindaun City * Shri Hardev Ji Maharaj Temple * Shri Raghunath Ji Temple *Shri Radha Raman Ji Temple Economy In 2006 the Ministry of Panchayati Raj named Karauli one of the country's 250 most backward districts (out of a total of 640). It is one of the twelve districts in Rajasthan currently receiving funds from the Backward Regions Grant Fund Programme (BRGF). Demographics According to the 2011 census Karauli district has a population of 1,458,248, roughly equal to the nation of Swaziland or the US state of Hawaii. This gives it a ranking of 340th in India (out of a total of 640). The district has a population density of . Its population growth rate over the decade 2001-2011 was 20.57%. Karauli has a sex ratio of 858 females for every 1000 males, and a literacy rate of 67.34%. At the time of the 2011 Census of India, 99.44% of the population in the district spoke Hindi and 0.53% Urdu as their first language.2011 Census of India, Population By Mother Tongue Meena and Gurjar caste dominates in Karauli. References External links *Karauli founded by Maharaja Arjun Dev Pal * Districts of Rajasthan Districts in Bharatpur division "
"El Kef ( '), also known as Le Kef, is a city in northwestern Tunisia. It serves as the capital of the Kef Governorate. El Kef is situated to the west of Tunis and some east of the border between Algeria and Tunisia. It has a population of (2004 census). The old town is built on the cliff face of the table-top Jebel Dyr mountain. El Kef was the provisional capital of Tunisia during World War II. It was the command centre of the Front de Libération Nationale during the Algerian War of Independence against the French in the 1950s. The Sidi Bou Makhlouf Mausoleum entombs the patron saint of the city. Geography Landscape near El Kef The highest-elevated city of Tunisia, at , its metropolitan area reaches of which lie within the interior of the old walled Medina quarter. The municipality of El Kef is shared between two national delegates, East Kef and West Kef, which correspond to the two municipal boroughs. History Ruins of Roman baths at the foot of the kasbah. Kasbah of Le Kef (17th and 18th century). Kasbah of Le Kef and surroundings. = Etymology = First known by the name of Sicca during the Carthaginian era, then later Sicca Veneria during the rise of Roman domination, the city has carried numerous names throughout its history: Colonia Julia Cirta, Cirta Nova, Sikka Beneria, Shaqbanariya and finally El Kef since the 16th century. =Ancient times= El Kef has since ancient times been the principal city of the High-Tell Mountains and of the Tunisian northwest of which it constituted, until recently, the political center, the most important religious center, and the dominant stronghold. In the early 5th century Apiarius of Sicca was a priest here, and instigated a dispute between the churches of Carthage and Rome concerning the jurisdiction of the Bishops of Africa when he appealed to the church of Rome against his excommunication by the church of Carthage. Around 439, invading Vandals conquered the African Romans near the coast. Eventually, El Kef became part of a Berber Kingdom. =Umayyad conquest= In 688 AD, the city was raided during the Umayyad conquest of North Africa. In the 17th century, a Kasbah of Le Kef was built to house a permanent garrison (ujaq); the construction was completed by the addition of fortified ramparts in 1740. This did not however prevent the taking and pillaging of the city by the Algerians in 1756, nor the occupation by the French military from 1881, following the partial collapse of the Ottoman Empire. On July 8, 1884, the authorities of the new French Protectorate declared El Kef a municipality, one of the first in the country.Hamilton Alexander Rosskeen Gibb, Johannes Hendrik Kramers, Bernard Lewis, Charles Pellat et Joseph Schacht, The Encyclopaedia of Islam, vol. IV, éd. Brill, Leyde, 1954, p. 403 =Contemporary= In 1973, there was a summit meeting here between the Tunisian president Habib Bourguiba and the Algerian president Houari Boumédiène. The latter proposed a constitution for a Tunisian-Algerian union which Bourguiba declined in favor of the development of economic cooperation between the two countries. Climate The climate is usually unstable, ranging from summer heat waves to winter snow blizzards. Main sights Domes of the Sidi Bou Makhlouf Mausoleum. El Kef contains a certain number of Islamic religious edifices, in its role as the center of a Sufic movement. The Sidi Bou Makhlouf Mausoleum holds the tomb of the founder of the Aissawa brotherhood in Tunisia, Sidi Bou Makhlouf. The El Qadriya mosque is also important to Sufism. A legacy of the old local Jewish community, the synagogue of the Ghriba is the object of veneration by Jews of the region, who come in pilgrimage each year during the week marked by the festival of Sukkot. In the city is the mausoleum of Ali Tukie, the father of Al-Husayn I ibn Ali at-Turki, founder of the Husainid dynasty which ruled Tunisia from 1705 to 1957. The vestiges, well preserved, of a three-naved Roman basilica dating from the beginning of the 5th century named Dar El Kous, dedicated to Saint Peter, have been discovered.François Baratte, Féthi Béjaoui et Zeïneb Ben Abdallah, Recherches archéologiques à Haïdra : miscellanea, 2, éd. École française de Rome, Rome, 1999, p. 73Charles Diehl, L'Afrique byzantine : histoire de la domination byzantine en Afrique. 533-709, éd. Franklin, New York, 1959, p. 422 The enormous Jugurtha Tableland mesa is visible from El Kef. Culture = Museums = The Museum of the Popular Arts and Traditions of El Kef, housed within a museum built in the 18th century, presents collections which retrace the social habits and customs which prevailed before the independence of the country. = Music = The Bou Makhlouf festival is held in July each year. The Saliha Festival is held once every other year. The latter takes its name from the singer Saliha who hails from the region. = Performing arts = It is the seat of the National Center for the Dramatic and Scenic Arts of El Kef. The city also organizes the festival of "24 hours of non-stop theatre". = Cuisine = The cuisine of El Kef has two recipes specific to the region. First, a typical regional bread, mjamaa or khobz el aid, is prepared at festival times, covered with an egg and decorated with pastry. Second, borzgane is a type of couscous lightly sweetened by alternating layers of dry fruits, dates, and lamb meat. The Festival of Mayou, also known as the Festival of Borzgane, brings the traditional Keffish couscous up to contemporary taste. Government The city council is composed of 22 members, including a president, vice president, borough chief, six assistants and thirteen counselors. Education Schools, institutes, and faculties include the El Kef Higher Institute of Applied Studies in the Humanities, El Kef Higher Institute of Music and Theatre, El Kef Higher Institute of Information Technology, El Kef Higher Institute of Physical Education, El Kef Graduate School of Agriculture, and El Kef Higher Institute of Nursing Science. Media Radio Le Kef, the regional radio service founded November 7, 1991, covers the northwest of the country. Transportation The transportation company of El Kef is the only company offering a public transit service by bus. The city is linked with surrounding cities by a network of taxis called louage, and with the capital, Tunis, by a regional railway line passing through Dahmani. Sports In sports, the Olympique du Kef, city soccer club founded in 1922 won the 2009-2010 League II Championship. The El Kef Higher Institute of Sport and Physical Education runs the annual Tunisian Women's Soccer Championship. Sister-city El Kef has had a sister-city relationship since 1993 with Bourg-en-Bresse, France, officially sealed in 1999 and 2000 with the signing of an agreement of exchange and friendship. Media references In 1855, John Henry Newman published a novel, Callista, which was set in Sicca Veneria in the 3rd century AD (Roman era). People *St. Fulgentius of Ruspe was ordered to be scourged here by an Arian priest in 499Butlers "Lives of the Saints" *Arnobius of Sicca Veneria (Arnobius the Elder) Notes and references Sources *Tahar Ayachi, El Kef, éd. Office national du tourisme tunisien, Tunis, 2007 *Abdelhamid Larguèche [sous la dir. de], Revoir El Kef, éd. MC-Editions, Carthage, 2005 *Camille Mifort, Vivre au Kef. Quand la Tunisie était française, éd. MC-Editions, Carthage, 2008 *Cornelia Smet, Si ma grand-mère était Keffoise, éd. MC-Editions, Carthage, 2005 External links *Site sur la ville du Kef *Voyage archéologique et historique aux origines de l'ancienne Cirta * Lexicorient Cities in Tunisia Communes of Tunisia History of Tunisia by location Roman sites in Tunisia Phoenician cities Populated places established in the 3rd century BC Maghreb "
"An L39 UV filter with a 55mm filter thread UV filters are compounds, mixtures, or materials that block or absorb ultraviolet (UV) light. One of the major applications of UV filters is their use as sunscreens to protect skin from sunburn and other sun/UV related damage. After the invention of digital cameras changed the field of photography, UV filters have been used to coat glass discs fitted to camera lenses to protect hardware that is sensitive to UV light. Background Earlier types of photographic film were quite sensitive to UV light, which used to cause haziness or fogginess, and a bluish hue in color film. UV filters were used to filter out shorter ultraviolet wavelengths while remaining transparent to visible light. However, the modern- day photographic film and digital cameras are less sensitive to UV wavelengths. UV filters are sometimes referred to as L37 or L39 filters, depending on the wavelengths of light they filter out. For example, an L37 filter removes ultraviolet light with wavelengths shorter than 370 nanometers (nm), whereas an L39 filter eliminates light with wavelengths shorter than 390 nm. Applications in printing and photography UV filters span the color spectrum and are used for a wide variety of applications. So-called Ortho Red and Deep Ortho Red lights are commonly used in diffusion transfer, in typesetting film or paper, and other applications dealing with orthochromatic materials. Yellow Gold, Yellow, Lithostar Yellow, and Fuji Yellow filters or safelights provide safe workspaces for contact proofing applications like screen printing and plate making. Pan Green, Infrared Green, and Dark Green filters or safelights are commonly used in scanning applications, work with panchromatic film, papers, and x-rays. Many photographers and cinematographers still use UV filters to protect their lenses' glass and coating. However, UV filters, as with any optical filter, may introduce lens flare and harm contrast and sharpness. Hoods can counteract this, as they offer some protection against impact and shade optical elements, thus preventing lens flare. Also, quality UV filters offer some protection against lens contamination while minimizing the inherent additional distortion. In photography, the term "UV filter" can also be misused as a filter that passes UV light while blocking other wavelengths in the light spectrum, in the same way, the term "IR filter" is used for filtering the entire spectrum. The correct name for such filters are "UV pass filter" and "IR pass filter" respectively, and they are only used in very specialized photography. Applications in personal care products Since excessive UV radiation can cause sunburn, photoaging, and skin cancer, care products such as sunscreen usually include a classification for the specific wavelengths they filter. UV classifications include UVA (320-400 nm), UVB (290-320 nm) and UVC (200-280 nm). UV-absorbing compounds are used not only in sunscreen, but also in other personal care products, such as lipstick, shampoo, hair spray, body wash, toilet soap, and insect repellent. Chemical filters protect against UV radiation by absorbing, reflecting, or scattering it. Reflection and scattering are accomplished by inorganic physical UV filters, such as titanium dioxide (TiO2) and zinc oxide (ZnO). Absorption, mainly of UVB, is done by organic UV filters, which are known as chemical UV filters. The levels of UV filters in sunscreens typically vary from 0.5% to 10%, although they sometimes reach 25%. =Examples of organic UV filters= Many different organic compounds can serve as UV filters. They fall into several structural classes: Environmental aspects The use of UV filters has increased recently due to growing concern about UV radiation and skin cancer, especially as a result of ozone depletion, which in turn has caused concern for its environmental impact. The filter material can enter the environment either directly, through industrial wastewater discharge, or indirectly, through domestic water discharge during showering, bathing, urine excretion or through wastewater treatment. Wastewater treatment plants (WWTP) are not very effective at removing these contaminants. Several UV filters have been detected at ppb or ppt levels in surface water and wastewater, with maximum concentrations in the summertime. Because most UV filters are lipophilic, they tend to bioaccumulate in aquatic environments and food chains originating from them. Confirming bioaccumulation, several studies have shown the presence of UV filters in aquatic organisms. The 4-methyl-benzylidene camphor was detected in the muscle tissue of trout in Swiss and German waters, while traces of Ethylhexyl methoxycinnamate and octocrylene were found in shellfish in the Mediterranean and Atlantic coasts of France. Furthermore, eighteen organic sunscreens were found in sediments of Japanese rivers and lakes, at concentrations ranging from 2 to about 3000 ng/g. The accumulation of organic UV filters in living organisms is of major concern because some of them (and their metabolites) can act as endocrine disruptors both in vitro and in vivo. Also, Goksøyr et al. (2009) reported concentrations of organic UV-filters in open waters of the Pacific Ocean, providing evidence of the persistence and wide dispersion of these components in the marine environment. Because UV-filters are not always stable under environmental conditions, it is common for them to transform into other compounds. Water in natural reservoirs, for example, is subjected to sun irradiation, while swimming-pool water is often disinfected by chlorination, bromination, ozonation, or UV irradiation. These byproducts can often be more toxic than the original UV filter. For example, avobenzone transforms in the presence of chlorinated disinfection products and UV radiation, producing substituted chlorinated phenols and acetophenones, which are known for their toxicity. Some organic UV filters under UV radiation can generate reactive oxygen species (ROS) (OH, H2O2) (e.g. BP-3, octocrylene (OCR), octyl methoxycinnamate (OMC), phenyl benzimidazole sulphonic acid (PBS, PABA, etc.). Some studies have recorded increased hydrogen peroxide or H2O2 levels in beaches directly attributable to UV filter transformation. H2O2 is responsible for damaging lipids, proteins and DNA, and generating high-stress levels in marine organisms. Inorganic UV-filters (i.e. TiO2) can also generate ROS, another compound toxic for marine phytoplankton. =Coral bleaching= Dipsastraea pallida (hard coral) with signs of bleaching or crown-of-thorns starfish damage UV filters have shown severe effects on coral reefs due to the bleaching of corals at very low concentrations. As a result, small quantities of sunscreens result in the production of large amounts of coral mucous within 18-48 hrs and bleaching of hard corals within 96 hrs. Among the UV filters that result in coral bleaching according to studies are Ethylhexyl methoxycinnamate, benzophenone-3, and 4-methyl benzylidene camphor, even in very low concentrations. Bleaching was favored by higher temperatures which act as synergistic factors. Experiments showed that the coral bleaching was not dose-dependent, so it can occur upon exposure to very small amounts. According to the rough estimate of 78 million tourists per year in coral reef areas, the estimated amount of sunscreen used annually in tropical countries ranges between 16,000 and 25,000 tons. 25% of this amount is washed off during bathing activities, leading to a release of 4,000-6,000 tons/year in the reef areas. This results in threatening 10% of the world reefs by sunscreen induced coral bleaching alone. Sunscreens can significantly enhance viral production in seawater. Mechanisms of transformation Photolysis of Benzophenone-3 in presence of Benzotriazole =Photolysis= Photolysis is the main abiotic route for the transformation of UV filters. Photolysis dissociates organic filters into free radicals. Photolysis can be direct or indirect. The direct way occurs when the chromophore of the organic filter absorbs sunlight at certain wavelengths. The indirect pathway occurs in the presence of a photo- sensitizer. Dissolved organic matter (DOM) in surface waters acts as a photo- sensitizer and produces reactive Photo-oxidation such as hydroxyl radicals, peroxyl radicals, and singlet oxygen. The photolysis of sunscreen products is more complicated than the behavior of individual UV filters, as shown by this example. In the presence of other UV filters, Benzotriazole, and humic acids, Benzophenone -3 degradation was observed through the loss of hydroxyl and benzoyl functional groups resulting in the formation of 2,4 dimethyl anisole. Photoisomerism =Photoisomerization= Photoisomerization can result in products that absorb less UV light than their parent compound. This is evidenced by cinnamates, salicylates, benzylidine camphor, and dibenzoylmethane derivatives. Octyl methoxycinnamate (OMC) can undergo photoisomerization, photodegradation, and photodimerization to obtain several dimers and cyclodimers isomers. Most commercial products are trans isomers but exist in the environment as a mixture of trans and cis isomers upon exposure to UV radiation due to the presence of the C=C double bond adjacent to the aromatic rings. The isomers may have identical physicochemical properties, but they may differ in biological behavior and effects. =Disinfection by- product= Swimming pool water is usually disinfected by chlorination, bromination, ozonation or UV radiation. Upon the presence of some UV filters such as Avobenzone in swimming pools, these can break down and create disinfection by-products, including toxic products, as a result of the interaction between Avobenzone and the active chlorine and UV radiation. Fate of some Organic UV filters =Benzophenones= Metabolic pathway of Benzophenone-3 Benzophenones (BPs) are widely used in UV filters, fragrance enhancers, and plastic additives. The major sources of BP-3 are reported to be human recreational activities and wastewater treatment plant (WWTP) effluents. The anionic forms of both BP-3 and 4-OH-BP3 can undergo direct photodegradation. The photolytic rates of both compounds in natural waters are faster than those in pure water. Radical scavenging experiments revealed that triplet-excited dissolved organic matter (3DOM*) was responsible for the indirect photodegradation of BP-3 and 4-OH-BP3 in seawater, whereas, in freshwater, the indirect photodegradation of these two compounds was attributed to Dissolved Organic Matter and OH radical. =P-aminobenzoic acid (PABA)= Indirect photolysis of p-aminobenzoic acid UV filter in water P-amino benzoic acid was one of the earliest UV filters used in sunscreens (1943). It was used in concentrations up to 5%. It was discovered by 1982 that PABA increases the formation of a particular DNA defect in human cells. The photochemical fate of PABA may be impacted by water constituents, e.g., NO3−, dissolved organic matter (DOM), and HCO3−. PABA undergoes both direct and indirect photolysis in the solution with the presence of NO3. Direct photolysis accounts for 25% of the degradation of PABA and is considered a secondary pathway. On the other hand, indirect photolysis was the dominant pathway. Zhou and Mopper showed that nitrate enhanced the photodegradation of PABA by a factor of 2. However, in the presence of free radical scavengers such as carbonate forms and natural organic matter (NOM), the photodegradation of PABA decreased. It was proposed that the indirect photolysis of PABA was mainly due to the NO3 photolysis product •OH. The Bicarbonate anion is abundant in water. Bicarbonate caused 10% of •OH scavenging. The reaction between bicarbonate and the •OH yields carbonate radical (•CO3), which is less reactive than •OH. In natural waters, •CO3 can reach a higher steady-state concentration than •OH because of its lower reactivity. The enhancement of PABA photolysis by bicarbonate is due to carbonate radicals. Water-soluble NOM is composed of organic acids. These organic acids are mainly humic substances, which can be categorized into a fulvic and humic acid fraction. NOM favors the indirect photolysis of PABA by absorbing the sunlight and weakening its intensity. Two reactions can take place during the degradation of PABA in the presence of nitrate in water as shown in the figure. Three of the four products contain phenolic groups and may thus be estrogenic. So the hazardous byproducts generated during the PABA photoreaction should be concerned for its estrogenicity. =4-tert-butyl-4’-methoxydibenzoylmethane (avobenzone)= Avobenzone tautomeric forms 4-tert-Butyl-4’-methoxydibenzoylmethane, known as avobenzone, belongs to dibenzoylmethanes. It is one of the most common UVA (400-320 nm) filters used in sunscreens formulations. It is sold under the trade names Parsol 1789 or Eusolex 9020. Avobenzone exists in two tautomeric forms: enol and keto. In sunscreen formulations, avobenzone exists predominantly in the enol form, which has a maximum absorption at wavelengths ranging from 350 to 365 nm depending on the solvent used. The double bond of the enolic form was shown to be more reactive in conditions of aquatic chlorination than the aromatic ring. In a chlorinated aquatic environment, Avobenzone transforms to two corresponding aldehydes and acids, as shown in the figure. Both aldehydes are formed as a result of the CO-CH2 bond. They are less stable in the oxidative conditions and easily transform into the corresponding acids. Chlorinated acetophenone derivatives are also formed due to the cleavage of the same CO-CH2 bond. Chlorinated acetophenone derivatives are tear gases, trigger dermatitis, and some other health problems. It was reported that chlorination of the original avobenzone into the aromatic ring position is less possible. The cleavage of the CO-Ar bond results in the formation of 4-chloroanisole. Avobenzone transformation products in chlorinated aquatic systems =Ethylhexyl methoxycinnamate (EHMC)= Ethylhexyl methoxycinnamate (EHMC) is one of the most common UVB filters used worldwide. It is known as Eusolex 2292 and Uvinul MC80. It is included in the High Production Volume Chemicals (HPVC) list, which includes chemicals produced or imported in the EU at a rate of more than 1000 tons per year. The lifetime of the EHMC was predicted to be from hours to a few days. EHMC is well tolerated by the skin. However, it has some side effects, including its ability to produce reactive oxygen species (ROS) and penetrate the human skin after exposure to UV light. EHMC has also been found in shellfish, fish, and cormorants at ng/g levels, which suggests that it can be accumulated in the food chain. EHMC was proved to be responsible for coral bleaching by promoting viral infections. From the toxicological point of view, EHMC has estrogenic properties both in vitro and in vivo. For instance, exposure to this compound caused the increase of the uterus' weight for rats. Prenatal exposure to EHMC can affect both the reproductive and neurological development in the offspring of rats, which can be a cause for concern because humans are routinely exposed to this compound through the use of sunscreens and other cosmetics. The main transformation pathway for EHMC is photolysis. Direct photolysis represents the dominant transformation pathway. On the other hand, the indirect photolysis due to OH is negligible and, due to dissolved organic matter, will be a secondary route. Four transformation products were detected for EHMC upon exposure to UV radiation. 4-methoxy benzaldehyde (MOBA) and 4-methoxy cinnamic acid are two transformation products of EHMC via dealkylation. The intermediate MOBA is more toxic than EHMC towards the bacteria. See also * Photographic filter References External links Optical filters "