Iodine was discovered as a novel element in 1811 during the Napoleonic Wars. To celebrate the bicentennial anniversary of this event we reflect on the history and highlight the many facets of iodine research that have evolved since its discovery. Iodine has an impact on many aspects of life on Earth as well as on human civilization. It is accumulated in high concentrations by marine algae, which are the origin of strong iodine fluxes into the coastal atmosphere which influence climatic processes, and dissolved iodine is considered a biophilic element in marine sediments. Iodine is central to thyroid function in vertebrates, with paramount implications for human health. Iodine can exist in a wide range of oxidation states and it features a diverse supramolecular chemistry. Iodine is amenable to several analytical techniques, and iodine compounds have found widespread use in organic synthesis. Elemental iodine is produced on an industrial scale and has found a wide range of applications in innovative materials, including semiconductorsin particular, in solar cells.

Commemorating two centuries of iodine research: An interdisciplinary overview of current research

This chapter presents a discussion on photochemistry and the cycling of carbon, sulfur, nitrogen, and Phosphorus. Dissolved organic matter (DOM) plays a dominant role in the absorption of ultraviolet (UV) and visible light in the open ocean. As DOM absorbance is regulated in part by photobleaching processes, light availability for photosynthesis and the penetration of UV radiation within the marine environment are influenced by photochemical transformations. In addition to its control on UV light fields, DOM photochemistry strongly impacts the biogeochemical cycling of biologically important elements in surface seawater. By the conversion of DOM into volatile species such as carbonyl sulfide, DOM photochemistry influences atmospheric chemistry and climate. The chapter illustrates an important light-driven chemical reaction in the photic zone—that is, the reduction of trace metals such as iron, manganese, and copper. The chemistry of these reduced species is quite different from their oxidized counterparts. Photochemical oxidation of DOM also produces a suite of free radicals and other short-lived species including the superoxide anion, carbonate radical, singlet oxygen, hydroxyl radical, di-bromide radical anion, and a number of poorly described organic radicals and excited state triplets. These species are much more reactive than their corresponding diamagnetic and ground state species and are expected to influence biological and chemical processes in sunlit surface waters. Furthermore, DOM photolysis is an important source or sink of a variety of atmospherically important gases that are emitted from the ocean, some of which affect the Earth's radioactive balance. Concentrations—and hence emissions—of carbon monoxide (CO), carbon dioxide (CO 2 ), carbonyl sulfide (OCS), and di-methyl sulfide (DMS) are all partly regulated through photochemical processes involving DOM.

Chapter 9 – Photochemistry and the Cycling of Carbon, Sulfur, Nitrogen and Phosphorus

Sensitive determination of iodine species, including organo-iodine, for freshwater and seawater samples using high performance liquid chromatography and spectrophotometric detection

https://hal-cea.archives-ouvertes.fr/cea-01270133/document

Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy

DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. A Toxicological Profile for Iodine, Draft for Public Comment was released in September 2001. This edition supersedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary. For information regarding the update status of previously released profiles, contact ATSDR at: vi Background Information The toxicological profiles are developed by ATSDR pursuant to Section 104(i) (3) and (5) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA or Superfund) for hazardous substances found at Department of Energy (DOE) waste sites. CERCLA directs ATSDR to prepare toxicological profiles for hazardous substances most commonly found at facilities on the CERCLA National Priorities List (NPL) and that pose the most significant potential threat to human health, as determined by ATSDR and the EPA. ATSDR and DOE entered into a Memorandum of Understanding on November 4, 1992 which provided that ATSDR would prepare toxicological profiles for hazardous substances based upon ATSDR=s or DOE=s identification of need. The current ATSDR priority list of hazardous substances at DOE NPL sites was announced in the Toxicological Profiles are a unique compilation of toxicological information on a given hazardous substance. Each profile reflects a comprehensive and extensive evaluation, summary, and interpretation of available toxicologic and epidemiologic information on a substance. Health care providers treating patients potentially exposed to hazardous substances will find the following information helpful for fast answers to often-asked questions. Chapter 1: Public Health Statement: The Public Health Statement can be a useful tool for educating patients about possible exposure to a hazardous substance. It explains a substance's relevant toxicologic properties in a nontechnical, question-and-answer format, and it includes a review of the general health effects observed following exposure. Chapter 3: Health Effects: Specific health effects of a given hazardous compound are reported by type of health effect (death, systemic, immunologic, reproductive), by route of exposure, and by length of exposure (acute, intermediate, and chronic). In addition, both human and animal studies are reported in this section. NOTE: Not all health effects reported in this section are necessarily observed in the clinical setting. Please refer to the Public Health Statement to identify general health effects observed following exposure. The following additional material can be ordered through the ATSDR Information Center: IODINE viii Case …

Toxicological profile for iodine

Dissolved organic iodine in marine waters: Determination, occurrence and analytical implications

The formation of iodide in inshore waters from the photochemical decomposition of dissolved organic iodine

Non-volatile dissolved organic iodine (DOI) can be a major, or even the dominant, species of dissolved I in coastal, inshore and estuarine waters. It can be converted to IO3- in the presence of an oxidizing agent and to I- by reacting it with a reducing agent. Depending on the exact experimental conditions, the yields of these reactions may not be quantitative. In previous analytical schemes for the determination of IO3-, I- and DOI in marine waters, if oxidation or reduction steps are involved and the concentrations of one or more species are estimated by difference, the presence of DOI can lead to an overestimation of the concentrations of the inorganic species determined by difference and an underestimation of the concentration of DOI. In two cruises covering the James River to the southern Chesapeake Bay and from the southern Chesapeake Bay to the Atlantic, above a salinity (S) of 2, the contribution of DOI to total I increased with decreasing salinity and reached a maximum of 80%. DOI, I- and IO3- were successively the dominant form of dissolved I at 0.1 30 in the Atlantic Ocean at the Bay mouth, respectively. Total I behaved conservatively (i.e., no evidence of consumption or production) during estuarine mixing during both cruises. In the southern Chesapeake Bay, total inorganic I was also approximately conservative. The primary process affecting the speciation of dissolved I was the conversion of IO3- to I-. In the James River estuary, there were indications of the conversion of both IO3- and I- to DOI. The concentrations of total I, IO3-, I- and DOI in James River water were 0.121, undetectable, 0.068 and 0.053 microM, respectively. These concentrations of total I and I- are significantly higher while that of IO3- is noticeably lower than those used presently for estimating global riverine input of these I species to the oceans. The riverine flux of DOI to the oceans is presently unknown.

Xian-Hao Cheng

Papers

Dissolved organic iodine in marine waters: Determination, occurrence and analytical implications

The formation of iodide in inshore waters from the photochemical decomposition of dissolved organic iodine

Dissolved organic iodine in marine waters: role in the estuarine geochemistry of iodine.

Dissolved inorganic and organic iodine in the Chesapeake Bay and adjacent Atlantic waters: Speciation changes through an estuarine system