European Chemicals Agency
The European Chemicals Agency is an agency of the European Union which manages the technical and administrative aspects of the implementation of the European Union regulation called Registration, Evaluation and Restriction of Chemicals. ECHA is the driving force among regulatory authorities in implementing the EU's chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and addresses chemicals of concern, it is located in Finland. The agency headed by Executive Director Bjorn Hansen, started working on 1 June 2007; the REACH Regulation requires companies to provide information on the hazards and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most used substances have been registered; the information is technical but gives detail on the impact of each chemical on people and the environment.
This gives European consumers the right to ask retailers whether the goods they buy contain dangerous substances. The Classification and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU; this worldwide system makes it easier for workers and consumers to know the effects of chemicals and how to use products safely because the labels on products are now the same throughout the world. Companies need to notify ECHA of the labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100 000 substances; the information is available on their website. Consumers can check chemicals in the products. Biocidal products include, for example, insect disinfectants used in hospitals; the Biocidal Products Regulation ensures that there is enough information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation; the law on Prior Informed Consent sets guidelines for the import of hazardous chemicals.
Through this mechanism, countries due to receive hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have serious effects on human health and the environment are identified as Substances of Very High Concern 1; these are substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment and do not break down. Other substances considered. Companies manufacturing or importing articles containing these substances in a concentration above 0,1% weight of the article, have legal obligations, they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy. Once a substance has been identified in the EU as being of high concern, it will be added to a list; this list is available on ECHA's website and shows consumers and industry which chemicals are identified as SVHCs.
Substances placed on the Candidate List can move to another list. This means that, after a given date, companies will not be allowed to place the substance on the market or to use it, unless they have been given prior authorisation to do so by ECHA. One of the main aims of this listing process is to phase out SVHCs where possible. In its 2018 substance evaluation progress report, ECHA said chemical companies failed to provide “important safety information” in nearly three quarters of cases checked that year. "The numbers show a similar picture to previous years" the report said. The agency noted that member states need to develop risk management measures to control unsafe commercial use of chemicals in 71% of the substances checked. Executive Director Bjorn Hansen called non-compliance with REACH a "worry". Industry group CEFIC acknowledged the problem; the European Environmental Bureau called for faster enforcement to minimise chemical exposure. European Chemicals Bureau Official website
Carbon is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds, it belongs to group 14 of the periodic table. Three isotopes occur 12C and 13C being stable, while 14C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity. Carbon is the 15th most abundant element in the Earth's crust, the fourth most abundant element in the universe by mass after hydrogen and oxygen. Carbon's abundance, its unique diversity of organic compounds, its unusual ability to form polymers at the temperatures encountered on Earth enables this element to serve as a common element of all known life, it is the second most abundant element in the human body by mass after oxygen. The atoms of carbon can bond together in different ways, termed allotropes of carbon; the best known are graphite and amorphous carbon. The physical properties of carbon vary with the allotropic form.
For example, graphite is opaque and black while diamond is transparent. Graphite is soft enough to form a streak on paper, while diamond is the hardest occurring material known. Graphite is a good electrical conductor. Under normal conditions, carbon nanotubes, graphene have the highest thermal conductivities of all known materials. All carbon allotropes are solids under normal conditions, with graphite being the most thermodynamically stable form at standard temperature and pressure, they are chemically resistant and require high temperature to react with oxygen. The most common oxidation state of carbon in inorganic compounds is +4, while +2 is found in carbon monoxide and transition metal carbonyl complexes; the largest sources of inorganic carbon are limestones and carbon dioxide, but significant quantities occur in organic deposits of coal, peat and methane clathrates. Carbon forms a vast number of compounds, more than any other element, with ten million compounds described to date, yet that number is but a fraction of the number of theoretically possible compounds under standard conditions.
For this reason, carbon has been referred to as the "king of the elements". The allotropes of carbon include graphite, one of the softest known substances, diamond, the hardest occurring substance, it bonds with other small atoms, including other carbon atoms, is capable of forming multiple stable covalent bonds with suitable multivalent atoms. Carbon is known to form ten million different compounds, a large majority of all chemical compounds. Carbon has the highest sublimation point of all elements. At atmospheric pressure it has no melting point, as its triple point is at 10.8±0.2 MPa and 4,600 ± 300 K, so it sublimes at about 3,900 K. Graphite is much more reactive than diamond at standard conditions, despite being more thermodynamically stable, as its delocalised pi system is much more vulnerable to attack. For example, graphite can be oxidised by hot concentrated nitric acid at standard conditions to mellitic acid, C66, which preserves the hexagonal units of graphite while breaking up the larger structure.
Carbon sublimes in a carbon arc, which has a temperature of about 5800 K. Thus, irrespective of its allotropic form, carbon remains solid at higher temperatures than the highest-melting-point metals such as tungsten or rhenium. Although thermodynamically prone to oxidation, carbon resists oxidation more than elements such as iron and copper, which are weaker reducing agents at room temperature. Carbon is the sixth element, with a ground-state electron configuration of 1s22s22p2, of which the four outer electrons are valence electrons, its first four ionisation energies, 1086.5, 2352.6, 4620.5 and 6222.7 kJ/mol, are much higher than those of the heavier group-14 elements. The electronegativity of carbon is 2.5 higher than the heavier group-14 elements, but close to most of the nearby nonmetals, as well as some of the second- and third-row transition metals. Carbon's covalent radii are taken as 77.2 pm, 66.7 pm and 60.3 pm, although these may vary depending on coordination number and what the carbon is bonded to.
In general, covalent radius decreases with higher bond order. Carbon compounds form the basis of all known life on Earth, the carbon–nitrogen cycle provides some of the energy produced by the Sun and other stars. Although it forms an extraordinary variety of compounds, most forms of carbon are comparatively unreactive under normal conditions. At standard temperature and pressure, it resists all but the strongest oxidizers, it does not react with hydrochloric acid, chlorine or any alkalis. At elevated temperatures, carbon reacts with oxygen to form carbon oxides and will rob oxygen from metal oxides to leave the elemental metal; this exothermic reaction is used in the iron and steel industry to smelt iron and to control the carbon content of steel: Fe3O4 + 4 C → 3 Fe + 4 COCarbon monoxide can be recycled to smelt more iron: Fe3O4 + 4 CO → 3 Fe + 4 CO2with sulfur to form carbon disulfide and with steam in the coal-gas reaction: C + H2O → CO + H2. Carbon combines with some metals at high temperatures to form metallic carbides, such as the iron carbide cementite in steel and tungsten carbide used as an abrasive and for making hard tips for cutting tools.
The system of carbon allotropes spans a range of extremes: Atomic carbon is a ver
Janssen Pharmaceutica is a pharmaceutical company headquartered in Beerse, Belgium. It was founded in 1953 by Paul Janssen. In 1961, Janssen Pharmaceutica was purchased by New Jersey-based American corporation Johnson & Johnson, became part of Johnson & Johnson Pharmaceutical Research and Development, now renamed to Janssen Research and Development, which conducts research and development activities related to a wide range of human medical disorders, including mental illness, neurological disorders and analgesia, gastrointestinal disorders, fungal infection, HIV/AIDS, allergies and cancer. Janssen and Ortho-McNeil Pharmaceutical have been placed in the Ortho-McNeil-Janssen group within Johnson & Johnson; the early roots of what would become Janssen Pharmaceutica date back to 1933. In 1933, Constant Janssen, the father of Paul Janssen, acquired the right to distribute the pharmaceutical products of Richter, a Hungarian pharmaceutical company, for Belgium, the Netherlands and Belgian Congo. On 23 October 1934, he founded the N.
V. Produkten Richter in Turnhout. In 1937, Constant Janssen acquired an old factory building in the Statiestraat 78 in Turnhout for his growing company, which he expanded during World War II into a four-storey building. Still a student, Paul Janssen assisted in the development of paracetamol under the name Perdolan, which would become well-known. After the war, the name for the company products was changed to Eupharma, although the company name Richter would remain until 1956. Paul Janssen founded his own research laboratory in 1953 on the third floor of the building in the Statiestraat, still within the Richter-Eurpharma company of his father. In 1955, he and his team developed their first drug: Neomeritine, an antispasmodic found to be effective for the relief of menstrual pain. On 5 April 1956, the name of the company was changed to NV Laboratoria Pharmaceutica C. Janssen. On 27 April 1957, the company opened a new research facility in Beerse, but the move to Beerse would not be completed until 1971-1972.
On 2 May 1958, the research department in Beerse became a separate legal entity, the N. V. Research Laboratorium C. Janssen. On 24 October 1961, the company was acquired by the American corporation Johnson; the negotiations with Johnson & Johnson were led by Frans Van den Bergh, head of the Board of Directors. On 10 February 1964, the name was changed to Janssen Pharmaceutica N. V. and the seat of the company in Turnhout was transferred to Beerse. The company was led by Bob Stouthuysen and Frans Van Den Bergh. When, in 1971-1972 the pharmaceutical production moved to Beerse, the move from Turnhout was completed. Between 1990 and 2004, Janssen Pharmaceutica expanded worldwide, the company grew in size to about 28000 employees worldwide. From the beginning, Janssen Pharmaceutica emphasized as its core activity research for the development of new drugs; the research department, established in Beerse in 1957, developed into a large research campus. In 1987, the Janssen Research Foundation was founded which performs research into new drugs at Beerse and in other laboratories around the globe.
Janssen Pharmaceutica became the Flemish company with the largest budget for research and development. Beside the headquarters in Beerse with its research departments, pharmaceutical production and the administrative departments, Janssen Pharmaceutica in Belgium still has offices in Berchem, a chemical factory in Geel, Janssen Biotech in Olen; the Chemical Production plant in Geel makes the active ingredients for the company’s medicines. In 1975, the first plant of a new chemical factory Plant I was established in Geel, Plant II was opened in 1977, Plant III' in 1984, Plant IV in 1995. In 1999 the remaining chemical production in Beerse was transferred to Geel. About 80% of its active components are manufactured here; the site in Geel manufactures about two-thirds of the worldwide chemical production of the pharmaceutical sector of Johnson & Johnson. In 1995, the Center for Molecular Design was founded by Paul Lewi. In 1999, clinical research and non-clinical development become a global organization within Johnson & Johnson.
In 2001, part of the research activities was transferred to the United States with the reorganization of research activities in the Johnson & Johnson Pharmaceutical Research Development organization. The research activities of the Janssen Research Foundation and the R. W. Johnson Pharmaceutical Research Institute were merged into the new global research organization. A new building for pharmaceutical development was completed in Beerse in 2001. In 2002, a new logistics and informatics centre was opened at a new site, Beerse 2. In 2003 two new research buildings were constructed, the Discovery Research Center, the Drug Safety Evaluation Center. On 27 October 2004, the Paul Janssen Research Center, for discovery research, was inaugurated. In March 2015, Janssen licensed tipifarnib to Kura Oncology who will assume sole responsibility for developing and commercialising the anti-cancer drug. In the same month the company announced that Galapagos Pharma and regained the rights to the anti-inflammatory drug candidate GLPG1690 as well as two other compounds including GLPG1205.
In May 2016, the company launched a collaboration MacroGenics and their preclinical cancer treatment, MGD015. The deal could net MacroGenics more than $740 million. In September 2017 it was announced that Janssen teamed up with the Biomedical Advanced Research and Development Authority (BARD
National Institutes of Health
The National Institutes of Health is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late 1870s and is now part of the United States Department of Health and Human Services; the majority of NIH facilities are located in Maryland. The NIH conducts its own scientific research through its Intramural Research Program and provides major biomedical research funding to non-NIH research facilities through its Extramural Research Program; as of 2013, the IRP had 1,200 principal investigators and more than 4,000 postdoctoral fellows in basic and clinical research, being the largest biomedical research institution in the world, while, as of 2003, the extramural arm provided 28% of biomedical research funding spent annually in the U. S. or about US$26.4 billion. The NIH comprises 27 separate institutes and centers of different biomedical disciplines and is responsible for many scientific accomplishments, including the discovery of fluoride to prevent tooth decay, the use of lithium to manage bipolar disorder, the creation of vaccines against hepatitis, Haemophilus influenzae, human papillomavirus.
NIH's roots extend back to the Marine Hospital Service in the late 1790s that provided medical relief to sick and disabled men in the U. S. Navy. By 1870, a network of marine hospitals had developed and was placed under the charge of a medical officer within the Bureau of the Treasury Department. In the late 1870s, Congress allocated funds to investigate the causes of epidemics like cholera and yellow fever, it created the National Board of Health, making medical research an official government initiative. In 1887, a laboratory for the study of bacteria, the Hygienic Laboratory, was established at the Marine Hospital in New York. In the early 1900s, Congress began appropriating funds for the Marine Hospital Service. By 1922, this organization changed its name to Public Health Services and established a Special Cancer Investigations laboratory at Harvard Medical School; this marked the beginning of a partnership with universities. In 1930, the Hygienic Laboratory was re-designated as the National Institute of Health by the Ransdell Act, was given $750,000 to construct two NIH buildings.
Over the next few decades, Congress would increase funding tremendously to the NIH, various institutes and centers within the NIH were created for specific research programs. In 1944, the Public Health Service Act was approved, the National Cancer Institute became a division of NIH. In 1948, the name changed from National Institute of Health to National Institutes of Health. In the 1960s, virologist and cancer researcher Chester M. Southam injected HeLa cancer cells into patients at the Jewish Chronic Disease Hospital; when three doctors resigned after refusing to inject patients without their consent, the experiment gained considerable media attention. The NIH was a major source of funding for Southam's research and had required all research involving human subjects to obtain their consent prior to any experimentation. Upon investigating all of their grantee institutions, the NIH discovered that the majority of them did not protect the rights of human subjects. From on, the NIH has required all grantee institutions to approve any research proposals involving human experimentation with review boards.
In 1967, the Division of Regional Medical Programs was created to administer grants for research for heart disease and strokes. That same year, the NIH director lobbied the White House for increased federal funding in order to increase research and the speed with which health benefits could be brought to the people. An advisory committee was formed to oversee further development of the NIH and its research programs. By 1971 cancer research was in full force and President Nixon signed the National Cancer Act, initiating a National Cancer Program, President's Cancer Panel, National Cancer Advisory Board, 15 new research and demonstration centers. Funding for the NIH has been a source of contention in Congress, serving as a proxy for the political currents of the time. In 1992, the NIH encompassed nearly 1 percent of the federal government's operating budget and controlled more than 50 percent of all funding for health research, 85 percent of all funding for health studies in universities. While government funding for research in other disciplines has been increasing at a rate similar to inflation since the 1970s, research funding for the NIH nearly tripled through the 1990s and early 2000s, but has remained stagnant since then.
By the 1990s, the NIH committee focus had shifted to DNA research, launched the Human Genome Project. The NIH Office of the Director is the central office responsible for setting policy for NIH, for planning and coordinating the programs and activities of all NIH components; the NIH Director plays an active role in shaping outlook. The Director is responsible for providing leadership to the Institutes and Centers by identifying needs and opportunities in efforts involving multiple Institutes. Within this Office is the Division of Program Coordination and Strategic Initiatives with 12 divisions including: Office of AIDS Research Office of Research on Women's Health Office of Disease Prevention Sexual and Gender Minority Research Office Tribal Heath Research Office Office of Program Evaluation and PerformancePrevious directors: Joseph J. Kinyoun, served August 1887 – April 30, 1899 Milton J. Rosenau, served May 1, 1899 – September 30, 1909 John F. Anderson, served October 1, 1909 – November 19, 1915 George W. McCoy, served November 20, 1915 – January 31, 1937 Lewis R. Thompson, served February 1, 1937 – January 31, 1942 R
Heparin known as unfractionated heparin, is a medication, used as an anticoagulant. It is used to treat and prevent deep vein thrombosis, pulmonary embolism, arterial thromboembolism, it is used in the treatment of heart attacks and unstable angina. It is given by injection under the skin. Other uses include inside test tubes and kidney dialysis machines. Common side effects include bleeding, pain at the injection site, low blood platelets. Serious side effects include heparin induced thrombocytopenia. Greater care is needed in those with poor kidney function. Heparin appears to be safe for use during pregnancy and breastfeeding. Heparin is a occurring glycosaminoglycan; the discovery of heparin was announced in 1916. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system; the wholesale cost in the developing world, when used for prevention, is about US$9.63–37.95 per month. In the United States it costs about $25–50 per month.
A fractionated version of heparin, known as low molecular weight heparin, is available. Heparin is a occurring anticoagulant produced by basophils and mast cells. In therapeutic doses, it acts as an anticoagulant, preventing the formation of clots and extension of existing clots within the blood. While heparin does not break down clots that have formed, it allows the body's natural clot lysis mechanisms to work to break down clots that have formed. Heparin is used for anticoagulation for the following conditions: Acute coronary syndrome, e.g. NSTEMI Atrial fibrillation Deep-vein thrombosis and pulmonary embolism Cardiopulmonary bypass for heart surgery ECMO circuit for extracorporeal life support Hemofiltration Indwelling central or peripheral venous cathetersHeparin and its low-molecular-weight derivatives are effective in preventing deep vein thromboses and pulmonary emboli in people at risk, but no evidence indicates any one is more effective than the other in preventing mortality. A serious side-effect of heparin is heparin-induced thrombocytopenia, caused by an immunological reaction that makes platelets a target of immunological response, resulting in the degradation of platelets, which causes thrombocytopenia.
This condition is reversed on discontinuation, in general can be avoided with the use of synthetic heparins. A benign form of thrombocytopenia is associated with early heparin use, which resolves without stopping heparin. Two non-hemorrhagic side-effects of heparin treatment are known; the first is elevation of serum aminotransferase levels, reported in as many as 80% of patients receiving heparin. This abnormality is not associated with liver dysfunction, it disappears after the drug is discontinued; the other complication is hyperkalemia, which occurs in 5 to 10% of patients receiving heparin, is the result of heparin-induced aldosterone suppression. The hyperkalemia can appear within a few days after the onset of heparin therapy. More the side-effects alopecia and osteoporosis can occur with chronic use; as with many drugs, overdoses of heparin can be fatal. In September 2006, heparin received worldwide publicity when three prematurely born infants died after they were mistakenly given overdoses of heparin at an Indianapolis hospital.
Heparin is contraindicated in those with risk of bleeding, severe liver disease, or severe hypertension. Protamine sulfate has been given to counteract the anticoagulant effect of heparin, it may be used in those who overdose on heparin or to reverse heparin's effect when it is no longer needed. Heparin's normal role in the body is unclear. Heparin is stored within the secretory granules of mast cells and released only into the vasculature at sites of tissue injury, it has been proposed that, rather than anticoagulation, the main purpose of heparin is defense at such sites against invading bacteria and other foreign materials. In addition, it is observed across a number of different species, including some invertebrates that do not have a similar blood coagulation system, it is a sulfated glycosaminoglycan. It has the highest negative charge density of any known biological molecule. In addition to the bovine and porcine tissue from which pharmaceutical-grade heparin is extracted, it has been extracted and characterised from: The biological activity of heparin within species 6–11 is unclear and further supports the idea that the main physiological role of heparin is not anticoagulation.
These species do not possess any blood coagulation system similar to that present within the species listed 1–5. The above list demonstrates how heparin has been evolutionarily conserved, with molecules of a similar structure being produced by a broad range of organisms belonging to many different phyla. In nature, heparin is a polymer of varying chain size. Unfractionated heparin as a pharmaceutical is heparin that has not been fractionated to sequester the fraction of molecules with low molecular weight. In contrast, low-molecular-weight heparin has undergone fractionation for the purpose of making its pharmacodynamics more predictable. Either UFH or LMWH can be used. Heparin binds to the enzyme inhibitor antithrombin III, causing a conformational change that results in its activation through an increase in the flexibility of its reactive site loop; the activated AT inactivates thrombin, factor Xa and oth
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons. Occurring tritium is rare on Earth, where trace amounts are formed by the interaction of the atmosphere with cosmic rays, it can be produced by irradiating lithium metal or lithium-bearing ceramic pebbles in a nuclear reactor. Tritium is used as a radioactive tracer, in radioluminescent light sources for watches and instruments, along with deuterium, as a fuel for nuclear fusion reactions with applications in energy generation and weapons; the name of this isotope is derived from Greek, Modern τρίτος, meaning'third'. While tritium has several different experimentally determined values of its half-life, the National Institute of Standards and Technology lists 4,500 ± 8 days, it decays into helium-3 by beta decay as in this nuclear equation: and it releases 18.6 keV of energy in the process. The electron's kinetic energy varies, with an average of 5.7 keV, while the remaining energy is carried off by the nearly undetectable electron antineutrino.
Beta particles from tritium can penetrate only about 6.0 mm of air, they are incapable of passing through the dead outermost layer of human skin. The unusually low energy released in the tritium beta decay makes the decay appropriate for absolute neutrino mass measurements in the laboratory; the low energy of tritium's radiation makes it difficult to detect tritium-labeled compounds except by using liquid scintillation counting. Tritium is produced in nuclear reactors by neutron activation of lithium-6; this is possible with neutrons of any energy, is an exothermic reaction yielding 4.8 MeV. In comparison, the fusion of deuterium with tritium releases about 17.6 MeV of energy. For applications in proposed fusion energy reactors, such as ITER, pebbles consisting of lithium bearing ceramics including Li2TiO3 and Li4SiO4, are being developed for tritium breeding within a helium cooled pebble bed known as a breeder blanket. High-energy neutrons can produce tritium from lithium-7 in an endothermic reaction, consuming 2.466 MeV.
This was discovered. High-energy neutrons irradiating boron-10 will occasionally produce tritium: A more common result of boron-10 neutron capture is 7Li and a single alpha particle. Tritium is produced in heavy water-moderated reactors whenever a deuterium nucleus captures a neutron; this reaction has a quite small absorption cross section, making heavy water a good neutron moderator, little tritium is produced. So, cleaning tritium from the moderator may be desirable after several years to reduce the risk of its escaping to the environment. Ontario Power Generation's "Tritium Removal Facility" processes up to 2,500 tonnes of heavy water a year, it separates out about 2.5 kg of tritium, making it available for other uses. Deuterium's absorption cross section for thermal neutrons is about 0.52 millibarns, whereas that of oxygen-16 is about 0.19 millibarns and that of oxygen-17 is about 240 millibarns. Tritium is an uncommon product of the nuclear fission of uranium-235, plutonium-239, uranium-233, with a production of about one atom per each 10,000 fissions.
The release or recovery of tritium needs to be considered in the operation of nuclear reactors in the reprocessing of nuclear fuels and in the storage of spent nuclear fuel. The production of tritium is not a goal, but rather a side-effect, it is discharged to the atmosphere in small quantities by some nuclear power plants. In June 2016 the Tritiated Water Task Force released a report on the status of tritium in tritiated water at Fukushima Daiichi nuclear plant, as part of considering options for final disposal of this water; this identified that the March 2016 holding of tritium on-site was 760 TBq in a total of 860000 m3 of stored water. This report identified the reducing concentration of tritium in the water extracted from the buildings etc. for storage, seeing a factor of ten decrease over the five years considered, 3.3 MBq/L to 0.3 MBq/L. According to a report by an expert panel considering the best approach to dealing with this issue, "Tritium could be separated theoretically, but there is no practical separation technology on an industrial scale.
Accordingly, a controlled environmental release is said to be the best way to treat low-tritium-concentration water." Tritium's decay product helium-3 has a large cross section for reacting with thermal neutrons, expelling a proton, hence it is converted back to tritium in nuclear reactors. Tritium occurs due to cosmic rays interacting with atmospheric gases. In the most important reaction for natural production, a fast neutron interacts with atmospheric nitrogen: Worldwide, the production of tritium from natural sources is 148 petabecquerels per year; the global equilibrium inventory of tritium created by natural sources remains constant at 2,590 petabecquerels. This is due to losses proportional to the inventory. According to a 1996 report from Institute for Energy and Environmental Research on the US Department of Energy, only 225 kg of tritium had been produced in the United States from 1955 to 1996. Since it continually de