AbstractWhile many terms are usually associated with suspended matter in the air, airborne particles or particulate matter (PM) generally refer to solid particles that may be composed of multiple phases (e.g., solids, liquid droplets, etc.). Airborne particles vary extensively in physical and chemical characteristics; their sizes can vary from tens of micrometers, that is, slightly smaller than beach sand or hair, to tens of nanometers. Solid airborne particles have been historically related to a wide range of occupational diseases such as various types of pneumoconioses (e.g., “black lung disease”), as well as less occupationally targeted respiratory illnesses such as acute respiratory irritation, asthma, or lung cancer. This chapter outlines airborne particles, its adverse health effects to workers in (1) areas with targeted production of particles and (2) in areas where exposure to ambient pollution is inevitable. This chapter presents metrics, techniques, exposure assessments, and biomarkers used for particulate measurements and routine monitoring. Also summarized in this chapter: its toxicity, mechanisms of attack, and carcinogenicity. Lastly, it tabulates existing standards both for the ambient and workplace and outlined some of the existing removal and control technologies. The ubiquity of airborne particles—from outdoor jobs, such as construction and firefighting, to indoor occupations, such as healthcare and custodial jobs, make it a central issue that is necessary to be addressed in any workplace area.
AbstractThis chapter is about a series of short‐chain per‐ and polyfluoroalkyl substances (PFAS). In the past, PFAS were described as fluorinated fatty acids or sulfonates. The overall structure of PFAS is a carbon chain with fluorine atoms substituting for hydrogen atoms. The resulting chemicals are chemically stable, water and oil resistant, and useful for many industrial applications, such as in the formation of polymers. The most notorious in this group are the fluorinated fatty acids (carboxylates) or sulfonates. In biological systems, these chemicals are generally well‐absorbed by the oral route and resistant to metabolism but also have the unusual property of having drastically different elimination kinetics between mammalian species.The available literature on this group of PFAS (C7 and below) is modest. This chapter will not attempt to review all this literature. Rather, human studies will be emphasized. Since human studies often suggest associations between PFAS exposure and health outcomes, these studies will be followed by definitive experimental animal studies that give insights into the human evidence. Afterward, a summary of attempts to estimate potential human risk by various international agencies will be described. What will become obvious, however, is that the overall uncertainty in the database of some of these chemicals has led to widely divergent risk assessment positions that need to be resolved. Risk management decisions on specific members of this class of chemistries are seen to be premature without such scientific resolution.
AbstractNaturally occurring ethers may be constituents of essential oils and may be extracted from these sources. Although some ethers may appear naturally, they may be prepared synthetically from other chemicals or other ethers.Symmetrical ethers are produced by the catalytic dehydration of their corresponding alcohols, for example, diethyl ether from ethanol. They are also obtained as by‐products from the formation of their corresponding esters or alcohols. Ethers may also be made by special synthesis procedures. Some ethers are obtained through the destructive distillation of selected hardwoods.Ethers have a wide variety of industrial uses. Their commercial value is recognized in the following industries: rubber, plastics, paints and coatings, refrigeration, medicine, dentistry, petroleum, chemical, perfume, cosmetics, toiletries, and food.The more volatile ethers have been used as liquid refrigerants, general anesthetics, commercial solvents, primers for gasoline engines, fuel additives, and rocket propellants. Other ethers have been used as alkylating agents in chemical syntheses of organic chemicals and in the manufacture of polymers. They are also used to denature alcohol. Halogenated ethers are used in the preparation of ion‐exchange resin, which is a modified polystyrene resin that is chloromethylated and then treated with a tertiary amine or with a polyamine. Ethers have wide use as commercial solvents and extractants for esters, gums, hydrocarbons, alkaloids, oils, resins, dyes, plastics, lacquers, and paints. They are used as dewaxing extractants for lubricating oils. Ethers have had limited use as cleaning and spotting agents. They are used as chemical intermediates in the manufacture of textile aids, such as dyes and resins. In the pharmaceutical industry, ethers are used as solvents, suspending agents, flavorings for oral drugs, and dental products. They are used to increase viscosity, as penetrants and wetting agents and as antioxidants and stabilizers. Ethers are used in foods as flavorings and in perfumes as fragrances. They are used as solvents for elastomers and for regenerating rubber. They have use as antiskinning agents in surface coatings and as weathering agents for paints and plastics. Ethers are also used in soaps. Ethers appear in heat transfer agents. Several industries use specific ethers for thickening, dispersing, suspending, binding, and film forming.The data presented here are arranged according to the chemical structure of the compounds. An effort has been made to place the chemicals within each group in an order that represents an increase in chain length. Even though the number of chemicals in any one group is limited, it is possible to make general, comparative statements. This corresponds with the acute toxicity data available in theNIOSH Registry of Toxic Effects of Chemical Substances.The oral toxicity and concentrated vapor data indicate that as the chain length increases in the symmetrical ethers, the toxicity is reduced. The inverse is true for skin penetration toxicity.
AbstractThe halogens are those elements in group XVII of the periodic table, and include fluorine, chlorine, bromine, iodine, and astatine, the latter of which is a radioactive element of no industrial importance. The physical properties of the halogens are described. They indicate an almost perfect doubling of atomic weights progressing from fluorine to bromine, paralleled by increases in specific gravity and melting and boiling points, and by decreases in water solubility.Chlorine and fluorine exist in the earth's crust in almost equal proportions (770 ppm for fluorine, 550 ppm for chlorine). The relative abundance of bromine and iodine are only about 2 and 0.04%, respectively, of that for chlorine. Seawater contains almost 19,000 ppm chlorine, compared to 65 ppm for bromine and less than 2 ppm for fluorine. Iodine exists only in trace quantities in seawater (about 0.05 ppm).Elements become progressively less electronegative and have less oxidizing potential as atomic weight increases. Each halogen forms an acid in water and combines with metals to form salts; the reactivity of these compounds shows the same relationship as the elemental halogens.Chemically, fluorine is the most powerful oxidizing agent known. It is the most reactive of all the elements. Free fluorine is rarely, if ever, found in nature. Elemental fluorine is produced on a commercial scale by electrolysis.Common operations where fluorine exposure occurs include the manufacture of fluorochemicals and plastics, rocket propellants, and fluorinated intermediates, metal production such as aluminum potroom work, the fluorination of pharmaceuticals and consumer products such as dentifrices, and the fluoridation of public drinking‐water supplies. Environmental contamination and air pollution with fluorine and fluorides may occur as a result of emissions from facilities for aluminum production, glass and ceramic manufacture, fertilizer manufacture, and the processing of fluorspar.Because of the reactivity of fluorine, exposures of humans and animals, and environmental contamination problems are almost always the result of fluorides, rather than fluorine gas. Most studies of fluorine itself are artificial and of academic rather than practical interest. Functionally, acute exposures to fluorine gas must be regarded as severe and potentially lethal corrosive exposures, with the added nuances of disturbances in calcium metabolism because of the reaction between the calcium ion and the fluoride ion.Chlorine is associated with the largest array of industrially useful compounds of all the halogens; it is the ninth highest volume chemical produced in the United States. Chemically, chlorine is more reactive than either bromine or iodine; it displaces bromine and iodine from their salts and enters into substitution and addition reactions with both inorganic and organic substances. When moist, but not when dry, chlorine unites directly with most elements. The physical properties of chlorine are given. Recognition of widespread environmental contamination problems associated with persistent chlorinated organic compounds has led to pressure to reduce the use of chlorinated compounds in industrial chemicals. The outcome of this concern is unclear at this time, but it is likely to lead to substitution of other compounds for those containing environmentally persistent and toxic chlorinated materials. Although most of the identified compounds that present environmental contamination problems are higher molecular weight organic compounds, the use of chlorinated solvents in cleaning and degreasing operations has already been reduced and will be further reduced because of their impact on the ozone layer. Higher molecular weight organic compounds containing chlorine have been identified as possible xenoestrogens. The concern of the scientific community is high, and much research is under way to clarify the role of halogenated xenoestrogens in biological systems. It is likely that if the halogenated organic compounds are confirmed to be biologically detrimental, there will be a further reduction in the production and use of these compounds. The introduction of chemically reactive inorganic halogens, principally chlorinated compounds, into the environment in groundwater and air may lead to active halogenation of natural products to xenoestrogens. If this pathway is confirmed, this, too, will lead to a reduction in the use of chlorinated compounds.Chlorine is noncombustible in air but will support the combustion of other materials. It reacts explosively or forms explosive mixtures with many common materials, including acetylene, turpentine, ammonia gas, fuel gas, hydrocarbons, hydrogen, and finely divided metals. Chlorine may also combine with water or steam to produce hydrogen chloride (HCl) fume.The reactivity of bromine lies between that of chlorine and iodine. Bromine will cause ignition of organic materials, including wood, cotton, and straw. It reacts violently on contact with natural rubber and reacts explosively with a number of common substances, including aldehydes, ketones, carboxylic acids, acetylene, acrylonitrile, ammonia, ethyl phosphine, hydrogen, nickel carbonyl, ozone, oxygen difluoride, phosphorus, potassium, sodium, and sodium carbide. Because of its explosive potential, facilities where bromine is manufactured or used should be designed to dispose rapidly of liquid bromine spills.Although it is estimated that 1015–1016 tons of bromine are contained in the earth's crust, it is widely distributed and found only in low concentrations in the form of bromide salts. The most readily recoverable form of bromine occurs as soluble salts in salt lakes, inland seas, brine wells such as those in Michigan and Arkansas, and seawater. Today, little bromine is extracted from seawater, which contains bromide salts in a concentration of only 65 ppm. The largest single current use of bromine is for the production of fire retardants.Agricultural chemical production consumed about 10% of bromine production, primarily as methyl bromide. However, recent restrictions on the use of brominated pesticides, such as ethylene dibromide and DBCP and proposed limitations on such fumigants as methyl bromide are expected to further reduce the use of these brominated chemicals in the future.Skin or eye contact with vapor or liquid bromine pentafluoride causes painful, deep‐seated, long‐lasting burns. The acute effect of this substance on the lung is similar to that of phosgene.Iodine is the 47th most abundant element in the earth's crust. The name iodine derives from the Greek word for violet‐colored,ioeides, which was used to describe the purple vapor generated by heating iodine. It is the heaviest of the halogens that are of industrial interest. Under ordinary conditions, iodine takes the form of gray‐black plates or granules that have a metallic, crystalline luster. It volatilizes at room temperature to yield a sublimed, violet vapor. Iodine's physical properties are shown.Although iodine resembles other members of the halogen group, it is the least electronegative; it is thus the least chemically reactive of the halogens and forms the weakest bonds with more electropositive elements.Iodine is used both in animal and human medicine, where its disinfectant and antiseptic properties are valued. The lack of iodine causes goiter (compensatory hypertrophy of the thyroid gland), and iodine is used both to treat iodine deficiency and hyperthyroidism. Principal iodine compounds and their industrial uses are shown.The inorganic iodine compounds of commercial interest, and their physical properties, are discussed. The iodides, an important class of inorganic iodine compounds, have less tendency to form complexes than the other halides. Chlorine and bromine freely displace iodine from the iodides. Iodine forms industrially useful and important compounds with hydrogen, metals, the other halogens, and oxygen. Those presented here are typical.
AbstractOrganic peroxides (ROOR′), solid or liquid with the bivalent OO structure. Relatively unstable and highly reactive molecules due to the presence of an oxygen–oxygen linkage. The oxygen–oxygen bond may be cleaved to form highly reactive free radicals and react with many substances (e.g., metals, acids, and bases). ROORs are used in plastics, rubbers, and many industries as initiators, accelerators, promoters, catalysts, activators, and more. Major concerns with ROORs are associated with fires, explosions, and corrosiveness. Reactive oxygen species and free radicals may lead to DNA damage and mutagenesis. Recent work from government agents, academic research laboratories, and manufacturing organizations have focused on physical hazards classification and categorization; and producing best practice protocols for safe handling and storage, control of temperatures, self‐accelerating decomposition temperatures, spills cleaning, disposal, and treatment of ROORs residues. These efforts allow compliance with countries and international regulations. Potential health hazards are associated with eye and skin contact, inhalation, and ingestion. Acute exposure may lead to irritation, allergic response, and potential damage to the eye and skin. As with any irritant or corrosive, dose is a critical consideration with respect to understanding the risk. Chronic exposures, mostly understood in animals but there are human data, can cause a myriad of effects. These may range from respiratory illnesses, to liver, kidney damage, and cancer. The manufacturer's SDS of individual chemical may provide toxicity information. This chapter summarizes chemical‐specific toxicity information on 77 organic peroxide compounds grouped in eight physical hazard categories. NIOSH has fully validated the method for benzoyl peroxide. NTP has released a report on the toxic effects oft‐butyl perbenzoate and it deserves to be considered. Exposure assessment methods when available were presented. Future research needs to focus on epidemiological and toxicological studies of ROORs.
AbstractThe term asbestos refers to two very different minerals, serpentine and amphibole, occurring in fibrous form with very different mineralogical properties. Unfortunately, the term “asbestos” has been used loosely when, in fact, it has always been appropriate to discuss them separately. This chapter focuses on the key essential differences which result in very different toxicological and epidemiological responses to the fibers from these two minerals. In particular, it is discussed how a fiber's potency dictates the health risk, how the fiber's mineralogy affects biopersistence in the lung, and how fiber length determines how the lung responds to this characteristic. The differential toxicology is presented, as well as the epidemiology of these fibrous minerals. The regulations in the United Stated are also discussed. It is now convenient to use the term asbestos to describe a subset of elongated mineral particles (EMPs). Although the term has been discussed with potential differing definitions depending on the authors' purpose from 1979 to 2023, a popular working definition for EMPs is any mineral particle with a minimum aspect ratio of 3:1. This chapter will focus on the asbestos subset.
Abstract This chapter is about a series of per‐ and polyfluoroalkyl substances (PFAS) that can also be described as “long‐chain” perfluoroalkyl acids (PFAAs). The overall structure of PFAAs is a lengthy carbon chain with fluorine atoms substituting for hydrogen atoms and either a carboxylic or sulfonate head group. PFAAs are unusually chemically stable, water and oil resistant, and useful for many industrial applications, such as in the formation of polymers. In biological systems, these chemicals are generally well‐absorbed, resistant to metabolism, but also have the unusual property of widely different elimination kinetics among and within mammalian species. The range of estimated elimination half‐lives in humans for the perfluorooctanoic acid (PFOA), for example, is quite large ranging from one‐half to as much as 14 years, although a recent estimate from an international collaboration places this value closer to 1 year. The available literature on PFAAs is voluminous. This chapter will not attempt to review all this literature. Rather human studies will be emphasized, but since these studies nearly always suggest associations between PFAA exposure and health outcomes, this will be followed by studies in experimental animals that give insights into the human evidence. Afterward, a summary of attempts to estimate potential human risk by various international agencies will be described. What will become obvious, however, is that the overall uncertainty in the database of these chemicals has led to widely divergent risk assessment positions that need to be resolved. Risk management decisions on this class of chemistries are seen to be premature without such scientific resolution.
AbstractThis chapter covers (1) esters of carbonic and orthocarbonic acid, (2) esters of organic phosphorous compounds, (3) esters of monocarboxylic halogenated acids, alkanols, or haloalcohols, and (4) organic silicon esters.
AbstractThis chapter is about a series of fluorinated polymers (fluoropolymers) which belong to a broad class of chemical substances referred to as per‐ and polyfluoroalkyl substances (PFAS). PFAS are a unique class of anthropogenic chemicals consisting of carbon and fluorine atoms joined by very strong bonds, resulting in high‐performance properties. The overall structure of these fluoropolymers is the covalent linkage of one or more monomers, at least one of which is generally short carbon chains with fluorine atoms substituting for hydrogen atoms. The resulting fluoropolymer is a much larger molecule with very different uses, kinetics, and potential toxicity than the constituent monomers. For example, fluoropolymers are generally not well‐absorbed, if at all, in biological systems, thus avoiding to a great degree of any untoward toxicity. Unlike the monomers, the resulting fluoropolymers are usually chemically stable, biologically inert and nonbioaccumulative, water and oil resistant, and useful for many industrial applications. Because the chemical structure of these fluoropolymers makes them generally biologically unreactive and chemically inert, the available epidemiology and toxicology literature is minimal. This chapter will review the literature on fluoropolymers but will also briefly discuss the toxicity of the constituent monomers. Afterward, a summary of estimates of potential human risk by various agencies will be described.For information and practical guidance on the use of terminology in regard to PFASs, readers are referred to the OECD PFAS Terminology report [OECD,Reconciling Terminology of the Universe of Per‐ and Polyfluoroalkyl Substances: Recommendations and Practical Guidance, OECD Series on Risk Management, No. 61, OECD Publishing, Paris, 2021. Available athttps://www.oecd.org/chemicalsafety/portal‐perfluorinated‐chemicals/terminology‐per‐and‐polyfluoroalkyl‐substances.pdf. Accessed October 10, 2023).
Abstract Refrigerants that were generally toxic and flammable in the early 1900s were eventually replaced with chlorofluorocarbons (CFCs) in the early 1930s. Since then, they have undergone significant evolution, mostly driven by regulatory actions. The evolution pattern involves an initial phaseout of CFCs to hydrochlorofluorocarbons (HCFCs) followed by hydrofluorocarbons (HFCs), and finally to the current products which include a double bond in their structure and are referred to as hydrofluoro‐olefins (HFOs) and hydrochlorofluoro‐olefins (HCFOs); the term hydro(chloro)fluoro‐olefins (H(C)FOs) is employed when referring to both HFOs and HCFOs. These chemicals were/are also used as foam‐blowing agents, solvents, and propellants. Unlike HFCs and HCFCs, which are saturated organic compounds, H(C)FOs are unsaturated organic compounds (olefins or alkenes) and are composed of hydrogen, fluorine, and carbon (HFOs), or hydrogen, chlorine, fluorine, and carbon (HCFOs). The evolution of these products has mostly been driven by regulatory actions that were aimed at addressing their environmental impact. Initial scrutiny was placed on their stratospheric ozone depletion effects and later on their impact on global warming. H(C)FOs are generally categorized as having zero ozone depletion potential (ODP) and low global warming potential (GWP) and are considered more environmentally friendly, making them suitable substitutes for CFCs, HCFCs, and HFCs. The H(C)FOs reviewed in this chapter have relatively low toxicity and do not pose any health concerns for humans or the environment under normal use conditions. Toxicity datasets for a select number of substances have been reviewed by external scientific committees such as WEEL and ASHRAE as well as various regulatory bodies. Toxicological summaries of five representative commercial H(C)FOs are described in this chapter.
Abstract Workers are exposed to carcinogens and carcinogenic exposure circumstances, as well as to many other agents considered probably, possibly, or reasonably anticipated to be human carcinogens. Covered herein are occupational carcinogens: chemicals, uncharacterized exposure circumstances, and occupations/workplaces known or suspected to cause cancer in workers, and agents causing cancers in animal bioassays, which are proven predictive for human cancers. Importantly, individuals differ in susceptibility for developing cancer due to exposure to a carcinogenic substance; factors influencing cancer outcomes include exposure circumstances, genetic differences, lifestyle, health condition, age, and gender. Identification of agents as carcinogens is based on information from epidemiological studies, long‐term animal studies, in vitro and in vivo evaluations, and assessments of mechanistic data and structure‐activity relationships. Various agencies, such as IARC, NTP, U.S. EPA, CalEPA, and others have developed classification schemes that categorize potential carcinogenicity of environmental and industrial agents in humans based on strength‐of‐evidence from human studies, animal studies, and mechanistic information. Categorizations formulated by authoritative bodies serve as the initial basis for standard's settings and regulatory actions. Several health and safety laws have been promulgated to protect workers from harmful effects of hazardous agents in the workplace. Risk characterization provides an integrative summary of available and relevant information on hazard identification, exposure assessment, and dose‐response relationships that have been used to estimate potential human cancer risks under various exposure circumstances. This information serves as the basis for risk management decisions on the extent to which workers' exposures to hazardous agents should be controlled. Likewise reducing or eliminating exposures to known and suspected carcinogens will reduce or prevent the incidences of occupational cancers. The World Health Organization reports occupational carcinogens are responsible for ∼152,000 cancer deaths per year and cancer prevention is essential because ∼40% of all cancer deaths can be prevented.
Abstract Aldehydes and acetals are both naturally occurring and the result of manufacturing processes, resulting in potential human exposures in occupational settings and from the ambient air and the use of consumer products. Aldehydes and acetals have been identified as genotoxicants, carcinogens, reproductive and developmental toxicants, and irritants. However, many also demonstrate limited toxicological effects at anticipated exposure levels in the general population. Here, 64 aldehydes and acetals are cataloged by sub‐class, chemical and physical properties, toxicological effects, and regulatory standards for occupational and general population cohorts. This summary of selected aldehydes and acetals represents the range of potential toxicological effects, which may cause difficulty in utilizing read‐across to predict the toxicity of aldehydes and acetals without toxicological data.
Abstract Propylene‐series glycol ethers are produced by the reaction of propylene oxide (PO) with primary alcohols. Chain prolongation occurs by further reaction of the glycol ether with excess propylene oxide during the production process. Therefore, a mixture of mono‐, di‐, tri‐, and higher propylene glycol ethers are formed, which are separated from each other by distillation. Due to the flexibility of using different alcohol groups and the number of propylene glycol ether linkages, P‐series glycol ethers can provide unique solvency characteristics by conveying both polar and nonpolar characteristics, and reduction of surface tension. Due to their physical–chemical characteristics, P‐series glycol ethers are used in many applications ranging from electronics to protective coatings and cleaners. The P‐series glycol ethers, and glycol ethers in general, have a robust toxicology data set covering a wide range of endpoints following oral, dermal, and inhalation routes of exposure. Due to the nature of the PO molecule, two structural isomers can be formed for each PO unit in the glycol ether molecule, i.e., two isomers for mono‐, four for di‐, eight for tri‐, and so on. The key difference is the resulting environment for the hydroxy group between the isomers. For the monos, the α‐isomer contains a secondary hydroxyl group (hence, sometimes also called the secondary isomer) whilst the β‐isomer has a primary hydroxyl group. This difference in hydroxyl group environment between the two isomers results in different metabolism routes being available, with higher toxicity from the β‐isomer due to its ability to oxidize to the acid form. It should be emphasized, however, that this predicted higher toxicity has only been seen with the β‐isomer of methoxypropanol. During production, the α‐isomer is thermodynamically favored and, when needed, the β‐isomer is controlled to reduce its presence. The P‐series glycol ether products as commercially produced are of low toxicity with the primary effects from long‐term exposure being adaptive changes to the liver and rat‐specific (α‐2μ‐globulin) kidney effects.
Abstract Beryllium, found in a variety of different forms, has become indispensable in modern high‐technology industries, especially aerospace. It has many attractive properties, including light weight, high strength, and heat resistance. Unfortunately, beryllium is associated with a number of toxic effects. Even under controlled conditions, beryllium metal, oxide, and alloys can cause chronic lung disease among individuals exposed to dust or fume. Identifying properties of different forms of beryllium are described in Section followed by sections which describe the properties and characteristics of beryllium. These include production and use, toxic effects, standards, and exposure assessment.
Abstract The chemicals in this chapter are C 2 to C 3 aliphatic hydrocarbons containing, chlorine, bromine, or iodine. All are volatile liquids (flammable and nonflammable) at ambient temperatures, except for ethyl chloride (gas) and hexachloroethane (solid). Most, if not all, of the chemicals in this chapter are produced in closed‐system facilities, and the majority are used, primarily or exclusively, as intermediates or feedstocks to produce other chemicals. 1,1,1‐Trichloroethane is an ozone‐depleting substance and is tightly regulated under the Montreal Protocol on Substances that Deplete the Ozone Layer. Three chemicals were not included in this edition: 1,1,2,2‐tetrabromoethane, 1,2‐dibromo‐3‐chloropropane (DBCP), and ethyl iodide. DBCP has been effectively banned as a soil fumigant due to its well‐characterized toxicity, particularly on male reproduction. For the other two chemicals, the toxicity information and use are limited.
AbstractPlatinum is ubiquitous in the human environment and is present in plants and animals, human food chains, airborne particles in inner‐city areas, and factory environments. It is a rare transitional metal with many uses in medicine, dentistry, and industrial applications. These include catalytic converters, electrical engineering, computers, space science, chemical syntheses, and jewelry. Platinum forms numerous durable alloys for clinical and industrial applications, and very many inorganic and organic compounds some of which are profound oxidizing agents and corrosive to skin and eyes. Others like the co‐ordination complexes, which are antimitotic through DNA binding, are potent anticancer drugs.The toxicity profile for platinum compounds is incomplete but permitted exposure levels (PEL) are shown for key materials. Respiratory distress, allergy, and hypersensitivity are principal hazards encountered through inhalation of airborne nanoparticles in mining, recycling, and emissions from vehicle exhaust systems. Metabolic pathways and excretion patterns involving liver and kidneys are discussed in relation to population studies. Urine analyses are clinical measures of platinum exposure. The anticancer/antimitotic drugs includingcis‐platin and carboplatin are clinically efficacious but cause nephrotoxicity, ear and sensi‐neural hearing, and possible carcinogenicity. Children are more sensitive.Experiments in animal models and cultured cells have contributed little in the understanding of hazards associated with platinum and related compounds. Whilst evidence of mutagenicity, DNA binding, clastogenicity is presented in standard laboratory screens, the 15th National Toxicology Program, Report on Carcinogens (2021) states thatcis‐platin should be reasonably anticipated to be a human carcinogen, despite no conclusive human epidemiological studies being available.
Abstract This chapter contains details on 12 unsaturated halogenated hydrocarbons. The considered chemicals are 1,3‐dichloropropene (DCP), cis ‐ and trans ‐1,2‐dichloroethylene (DCE), dichloroacetylene (DCA), allyl chloride (AC), hexachlorobutadiene (HCBD), β‐chloropropene, vinylidene chloride (VDC), vinyl chloride (VC), vinyl bromide (VB), vinyl fluoride (VF), trichloroethene (TCE), and tetrachloroethene (PCE). These compounds are used as fumigants, pesticides, solvents, and chemical intermediates. This chapter follows the outline determined for compounds and includes physical and chemical properties, production and use, exposure assessment in air and workplace, toxic effects (experimental and epidemiological studies), community methods for monitoring, regulations, and guidelines.
Abstract Endocrine disruption is a relatively new field of study, as endocrine disruptors were not formally acknowledged by regulatory agencies until 1996. Over the years, many federal and international regulatory agencies and professional associations have provided varying terminology and classifications; however, in general, exposure to endocrine disruptors, or endocrine‐disrupting chemicals (EDCs), at environmentally relevant doses results in adverse effects consequent to interfering with endocrine function. Apart from minor nomenclature disagreements, there are challenges and limitations to this field, as EDC classification criteria can vary substantially in considering evidence for a biologically plausible causal relationship between the endocrine activity and the induced adverse effect. Accordingly, international consensus for unambiguous designation of EDCs is lacking. Therefore, this chapter will not attempt to resoundingly identify all known or suspected EDCs; rather, the objective of this chapter is to first provide historical context to chemical regulation, including on endocrine disruption and its development as a field, and then follow with a review of the health implications, which highlights some fundamental concepts of endocrine disruption and incorporates a tale of the infamous public health disaster resulting from prescribing pregnant women diethylstilbestrol (DES), a potent synthetic estrogen. The current testing guidelines and standards for EDCs are also reviewed, demonstrating the restricted focus on canonical endocrine disruption that is characterized by nuclear hormone receptor‐based activity and the estrogenic, androgenic, thyroidal, and steroidogenic (EATS) modalities. To end, some of the more recently regulated EDCs, particularly bisphenol A and phthalates, as well as other ubiquitous EDCs, like phytoestrogens and flame retardants, are reviewed.
AbstractNanotechnology is a broad and rapidly developing field resulting in the inclusion of engineered nanomaterials (ENMs) into a number of products, applications, and processes. Due to the increased usage and production of ENMs, they represent an emerging exposure of toxicological concern among workers during ENM manufacturing and handling. The major routes of ENM exposure in occupational settings include inhalation, dermal contact, and potential ingestion. To date, a limited number of exposure assessments have been performed in industrial settings and few specific regulatory guidelines have been established. An increasing number of toxicology evaluations have suggested the potential for various adverse effects following ENM exposure. For example, in industrial settings, workers with longer exposures to ENMs have higher incidences of lung diseases, gastrointestinal tract alteration, hepatic injuries, reproductive failure, and neurological disorders. This chapter specifically focuses on ENMs that are currently or projected to be highly utilized in industrial settings including carbon nanotubes, graphene, fullerene, zinc oxide, silver, titanium oxide, cerium oxide, gold, and iron oxide. For each of these ENMs current suggested regulatory standards are provided. Further, findings from exposure assessment studies are described to determine exposure risks related to distinct ENMs and specific duties in the workplace. Toxicity data from human and animal studies are included to identify biological responses and adverse health effects potentially related to distinct ENM exposures. Throughout the chapter, critical gaps in our knowledge in regard to workplace ENM exposures and risk are highlighted.
