Toward a Typology of Dynamic and Hazardous Work Environments

The most hazardous work environments share one feature in common: constant change. Many different, but constantly changing hazards are found in agriculture, construction, mining, and transport. This dynamic feature of workplace hazards varies by: (1) degree of control, (2) predictability, (3) visibility, (4) movement, and (5) degree of speed and force. In some cases the actions of the dynamic hazards are required for production to take place, and in many cases, several different hazards may overlap and interact. Finally, whether intentional or unintentional, some dynamic hazards are human generated. These are some of the features that distinguish dynamic and hazardous work environments across a variety of industries. The authors propose a preliminary typology of dynamic and hazardous work environments, along with a schema to systematically observe the dynamic characteristics of these hazards. The implications of this typology are considered with respect to worker training, hazard awareness, and safe work practices. For example, the implementation of the Hierarchy of Control is shown to require active worker involvement at every level in the hierarchy, except where an environmental hazard has been completely eliminated.     

Identification of Risks in the Life Cycle of Nanotechnology‐Based Products

In order to realize the projected market potential of nanotechnology, the environmental, health, and safety (EHS) uncertainties posed by a nano‐product (i.e., a nanotechnology‐enabled product) need to be characterized through the identification of risks and opportunities in early stages of product development. We present a methodology to identify risks from nano‐products using a scenario analysis approach that allows for expert elicitation on a set of preidentified use and disposal scenarios and what we have labeled “risk triggers” to obtain scores on their likelihood of occurrence and severity. Use and disposal scenarios describe product life‐cycle stages that could result in risk attributed to the nano‐product, whereas risk triggers are particular to nanoparticle properties. These are potential risks, as the risk assessment community is currently debating the specific risks attributed to nanotechnology. Through such a framework, our goal is to identify which products pose greater risks, where these risks occur in the product life cycle, and the impacts of these environmental risks on society. The comparison of risk triggers across nano‐products allows relative risk ranking on axes of exposure‐ and hazard‐related risk triggers. For the specific case of air fresheners, areas of acute risks resulted from bioavailability of nanoparticles in air release and water entrainment exposure scenarios; catalytic activity of nanoparticles in inhalation and air release exposure scenarios; the harmful effects due to the antibacterial property on useful bacteria particularly in susceptible populations; and, finally, risks from the lack of nanoparticle coating stability in air release scenarios.     

Air pollution due to «Do-it-yourself» activities at home

Summary Do-it-yourself work as a leisure activity contributes to air pollution in homes. The products or materials handled while working may be dispersed in the air, in the form of gas, vapors or particles which, by penetrating the organism, may represent a genuine risk of intoxication. This air pollution source is of importance for two reasons: the number of amateurs of do-it-yourself work at home is steadily increasing and the products or materials and techniques formerly reserved to professionals are now available to anybody. The most frequently used health hazard products are the solvents, which are present in paints, varnishes, glues, protective wood coatings and paint strippers. Techniques such as the stripping of paint by means of heat and autogenous or electrical welding produce metal fumes, the noxiousness of which is well-known by all specialists in occupational toxicology. The hazards of acute intoxication affecting persons exposed to a high concentration of polluting agents in the air, during a short period of time, are those occuring most frequently during craftwork at home. Nevertheless, certain particular jobs may be carried out over periods long enough to generate risks of chronic intoxication. In comparison with the intoxication hazards in the professional field, those due to craftwork at home seem to be subject to three aggravation factors: the lack of knowledge of users, insufficient technical prevention and the absence of medical or toxicological control. The prevention of toxicological hazards due to do-it-yourself jobs effectuated at home is achieved through the information of the general public and that of the general practitioners. The knowledge about the risks incurred would lead the craftsmen to take efficient preventive measures. The doctors should draw the attention of their patients to the incompatibility existing between certain pathologic conditions and the fact of handling chemical products. They should also take account of possible toxic etiologies at the moment of diagnosing.     

Design of recycling system for poly(methyl methacrylate) (PMMA). Part 2: process hazards and material flow analysis

Introduction

In this series of papers, we present a design of poly(methyl methacrylate) (PMMA) recycling system considering environmental impacts, chemical hazards, and resource availability. We applied life cycle assessment (LCA), environment, health, and safety (EHS) assessment as well as material flow analysis to the evaluation of the recycling system.

Purpose

Recycling systems for highly functional plastics such as PMMA have not been studied sufficiently. Along with the popularization of PMMA-containing products such as liquid crystal displays (LCDs), the use of PMMA is steadily increasing, which will result in more waste of PMMA in the next decades. In this study, pyrolysis process for recycling waste PMMA into methyl methacrylate (MMA) monomer was examined, considering not only general environmental impacts quantified by life cycle assessment but also local environment, health, and safety hazards, and raw material availability.

Methods

Process EHS hazards assessment was applied to quantify the local effects of the PMMA monomer recycling process. Process hazards are strongly connected with the hazardous properties of chemical substances and stream conditions within the process. Two alternative cooling methods exist, and their difference was analyzed by LCA and EHS assessment. Besides the process hazard, the availability of waste PMMA must be an important point for the feasibility of implementing the PMMA monomer recycling process. The available amount can be quantified by analyzing the material flow of PMMA-containing products. PMMA contained in LCDs as light guide panels was selected as a feasible source of waste PMMA, and the quantity of PMMA flows in the society was evaluated.

Results and discussion

In the case of PMMA, monomer recycling has less process hazard than the production of fresh MMA from crude oil. The implementation of circulated cooling water could significantly decrease the process hazard in PMMA pyrolysis attributable to chemical hazards. Material flow analysis revealed that the availability of waste PMMA shows a fluctuating trend in the next 20 years because of the sharp peak demand for LCD television sets. The fluctuation is strongly dependent on the lifetime of LCD television sets.

Conclusions

PMMA monomer recycling has a potential to reduce environmental impacts with a less process hazards than fresh MMA production from crude oil. The availability of waste PMMA has a strong relationship with the lifetime of LCD television sets. The multiple and comprehensive assessments can reveal various aspects of a process technology.     

Modulation of oxidative damage by nitroxide free radicals

Piperidine nitroxides like 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) are persistent free radicals in non-acidic aqueous solutions and organic solvents that may have value as therapeutic agents in medicine. In biological environments, they undergo mostly reduction to stable hydroxylamines but can also undergo oxidation to reactive oxoammonium compounds. Reactions of the oxoammonium derivatives could have adverse consequences including chemical modification of vital macromolecules and deleterious effects on cell signaling. An examination of their reactivity in aqueous solution has shown that oxoammonium compounds can oxidize almost any organic as well as many inorganic molecules found in biological systems. Many of these reactions appear to be one-electron transfers that reduce the oxoammonium to the corresponding nitroxide species, in contrast to a prevalence of two-electron reductions of oxoammonium in organic solvents. Amino acids, alcohols, aldehydes, phospholipids, hydrogen peroxide, other nitroxides, hydroxylamines, phenols and certain transition metal ions and their complexes are among reductants of oxoammonium, causing conversion of this species to the paramagnetic nitroxide. On the other hand, thiols and oxoammonium yield products that cannot be detected by ESR even under conditions that would oxidize hydroxylamines to nitroxides. These products may include hindered secondary amines, sulfoxamides and sulfonamides. Thiol oxidation products other than disulfides cannot be restored to thiols by common enzymatic reduction pathways. Such products may also play a role in cell signaling events related to oxidative stress. Adverse consequences of the reactions of oxoammonium compounds may partially offset the putative beneficial effects of nitroxides in some therapeutic settings.     

Environmental Assessment of Waste-Solvent Treatment Options

A comparison of various waste‐solvent treatment technologies, such as distillation (rectification) and incineration in hazardous‐waste‐solvent incinerators and cement kilns, is presented for 45 solvents with respect to the environmental life‐cycle impact. The environmental impact was calculated with the ecosolvent tool that was previously described in Part I of this work. A comprehensive sensitivity analysis was performed, and uncertainties were quantified by stochastic modeling in which various scenarios were considered. The results show that no single treatment technology is generally environmentally superior to any other but that, depending on the solvent mixture and the process conditions, each option may be optimal in certain cases. Nevertheless, various rules of thumb could be derived, and a results table is presented for the 45 solvents showing under which process conditions and amount of solvent recovery distillation is environmentally superior to incineration. On the basis of these results and the ecosolvent tool, an easily usable framework was developed that helps decision makers in chemical industries reduce environmental burdens throughout the solvent life cycle. With clear recommendations on the environmentally optimized waste‐solvent treatment technology, the use of this framework contributes to more environmentally sustainable solvent management and thus represents a practical application of industrial ecology.     

Influence of phytochemicals on the biocompatibility of inorganic nanoparticles: a state-of-the-art review

Inorganic nanoparticles (NPs) are among the most produced NPs that could be used in consumer products and as healthcare materials, however, the intrinsic toxicity particularly through the mechanism associated oxidative stress raises the health concern about inorganic NP exposure. Phytochemicals are bioactive metabolites derived from plants as well as non-pathogenic microorganisms living within plants and have been shown to be beneficial to human health with their anti-aging, anti-cancer, anti-inflammation and anti-oxidant properties. In the present review, the influence of on the biocompatibility of inorganic NPs was discussed. It has been shown that phytochemicals could be used as bio-friendly capping agents for green synthesis of inorganic NPs, and phytochemical coated inorganic NPs were remarkable stable and biocompatible with high therapeutic efficiency. Meanwhile, the presence of phytochemicals was also able to reduce the side effects and enhance the therapeutic abilities of inorganic NPs, which is likely attributed to the anti-oxidative properties of phytochemicals. Thus, using phytochemicals could be a promising and plausible way to reduce side effects and increase the biocompatibility of inorganic NPs for biomedical applications.     

Application of a direct toxicity assessment approach to assess the hazard of potential pesticide exposure at selected sites on the Crocodile and Magalies rivers,South Africa

The potentially hazardous effects of agricultural pesticide usage in the Crocodile (west) Marico catchment were evaluated using the Danio rerio and Daphnia pulex lethality, Selenastrum capricornutum growth inhibition and the Ames mutagenicity plate incorporation assays. Hazard assessment categories are proposed to standardise the output of the different toxicity assessments. Sites were categorised according to the toxicity hazard indicated and were related to the gradients of agricultural land-use intensity at each site. Intensive agricultural sites showed the highest effects to all tested biota. Receiving water at urban sites associated with increased nutrients and lowest pesticide usage showed few adverse effects, while the relatively unimpacted site indicated no hazard to any organism, and only a slight stimulation to algal growth. Weighted hazard scores indicated that the unimpacted sites were least hazardous, falling within a B category, the urban sites were moderately hazardous (C category), and the agricultural sites (D category) had the highest potential impacts on aquatic organisms. This study demonstrated the usefulness of using the hazard assessment approach and the role it could play in assessing site-specific potential toxicity hazards of river water impacted by agrochemicals. It can be used together with other assessment methods, such as biological indices, in a tiered approach.     

The Cement Industry as a Scavenger in Industrial Ecology and the Management of Hazardous Substances

The cement industry uses a variety of secondary materials and fuels, thus fulfilling the role of "scavenger" in industrial ecology (IE). The use of wastes in cement production has been advocated to reduce cement production costs and to achieve the degradation and immobilization of hazardous compounds. In dealing with hazardous elements contained in the wastes, this development has side effects such as relatively significant stack emissions of heavy metals and leaching of hazardous compounds during the life cycle of cement-derived products. Emissions and leaching potential may be substantially lowered by reducing levels of hazardous elements in wastes before they are included in cement production and by selectively capturing mercury from stack gases. An analogy to metabolic functions of selective uptake, sequestration, and selective excretion is presented.     

Man-made mineral (vitreous) fibres: evaluations of cancer hazards by the IARC Monographs Programme

Man-made vitreous (glass-like) fibres are non-crystalline, fibrous inorganic substances (silicates) made primarily from rock, slag, glass or other processed minerals. These materials, also called man-made mineral fibres, include glass fibres (used in glass wool and continuous glass filament), rock or stone wool, slag wool and refractory ceramic fibres. They are widely used for thermal and acoustical insulation and to a lesser extent for other purposes. These products are potentially hazardous to human health because they release airborne respirable fibres during their production, use and removal. Man-made mineral fibres and man-made vitreous fibres have been the subject of reviews by IARC Monographs Working Groups in 1987 and 2001, respectively, which resulted in evaluations of the carcinogenic hazard to humans from exposure to these materials. These reviews and evaluations have been published as Volumes 43 and 81 of the IARC Monographs series [IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, vol. 43, Man-made Mineral Fibres and Radon (1988); IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, vol. 81, Man-made Vitreous Fibres (2002)]. The re-evaluation in 2001 was undertaken because there have been substantial improvements in the quality of the epidemiological information available on the carcinogenicity to humans of glass fibres, continuous glass filament and rock/slag wool. The new evaluations have addressed the limitations of earlier cohort studies, particularly concerning the lack of adjustment with respect to concomitant risk factors such as smoking and other sources of occupational exposure. In addition, the evaluation of the evidence for carcinogenicity of glass fibres to experimental animals has been refined, by making a distinction between insulation glass wool and special-purpose glass fibres. The results of the evaluations in 1987 and 2001 are thus different in several aspects. In this paper, the reviews and evaluations of the carcinogenic hazards of exposure to man-made mineral fibres (MMMF, Monograph volume 43, [1]) and man-made vitreous fibres (MMVF, Monograph volume 81, [2]) are summarised, and the differences explained. In particular, the considerations of the respective IARC Monographs Working Groups (1987, 2001) in reaching their conclusions are discussed in some detail.     

Composite Hazard Functions Reflecting Competing Latent Processes

A method for fitting parametric models to apparently complex hazard rates in survival data is suggested. Hazard complexity may indicate competing causes of failure. A competing risks model is constructed on the assumption that a failure time can be considered as the first passage time of possibly several latent, stochastic processes competing in reaching a barrier. An additional assumption of independence between the hidden processes leads directly to a composite hazard function as the sum of the cause specific hazards. We show how this composite hazard model based on Wiener processes can serve as a flexible tool for modelling complex hazards by varying the number of processes and their starting conditions. An example with real data is presented. Parameter estimation and model assessment are based on Markov Chain Monte Carlo methods. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Drug delivery and nanoparticles:applications and hazards

The use of nanotechnology in medicine and more specifically drug delivery is set to spread rapidly. Currently many substances are under investigation for drug delivery and more specifically for cancer therapy. Interestingly pharmaceutical sciences are using nanoparticles to reduce toxicity and side effects of drugs and up to recently did not realize that carrier systems themselves may impose risks to the patient. The kind of hazards that are introduced by using nanoparticles for drug delivery are beyond that posed by conventional hazards imposed by chemicals in classical delivery matrices. For nanoparticles the knowledge on particle toxicity as obtained in inhalation toxicity shows the way how to investigate the potential hazards of nanoparticles. The toxicology of particulate matter differs from toxicology of substances as the composing chemical(s) may or may not be soluble in biological matrices, thus influencing greatly the potential exposure of various internal organs. This may vary from a rather high local exposure in the lungs and a low or neglectable exposure for other organ systems after inhalation. However, absorbed species may also influence the potential toxicity of the inhaled particles. For nanoparticles the situation is different as their size opens the potential for crossing the various biological barriers within the body. From a positive viewpoint, especially the potential to cross the blood brain barrier may open new ways for drug delivery into the brain. In addition, the nanosize also allows for access into the cell and various cellular compartments including the nucleus. A multitude of substances are currently under investigation for the preparation of nanoparticles for drug delivery, varying from biological substances like albumin, gelatine and phospholipids for liposomes, and more substances of a chemical nature like various polymers and solid metal containing nanoparticles. It is obvious that the potential interaction with tissues and cells, and the potential toxicity, greatly depends on the actual composition of the nanoparticle formulation. This paper provides an overview on some of the currently used systems for drug delivery. Besides the potential beneficial use also attention is drawn to the questions how we should proceed with the safety evaluation of the nanoparticle formulations for drug delivery. For such testing the lessons learned from particle toxicity as applied in inhalation toxicology may be of use. Although for pharmaceutical use the current requirements seem to be adequate to detect most of the adverse effects of nanoparticle formulations, it can not be expected that all aspects of nanoparticle toxicology will be detected. So, probably additional more specific testing would be needed.     

Environmental issues in the planned release of genetically-engineered organisms

This paper examines issues concerned with the environmental release of genetically-engineered micro-organisms. Besides the obvious social and economic benefits from the technology, genetically-engineered micro-organisms can have considerable beneficial effects on environmental concerns, such as the degradation of pollutants and toxic chemical wastes, and less use of hazardous pesticides and chemicals. There may be uncertain negative effects arising from the technology. The hazards of the technology and possible policy approaches are discussed. It is concluded that, overall, the applications arising from this technology are likely to be benign, because its effects on the environment can largely be anticipated by an increase in scientific knowledge gained from field trials and greater experience with releases.     

Toxicity of inorganic nanomaterials in biomedical imaging

Inorganic nanoparticles have shown promising potentials as novel biomedical imaging agents with high sensitivity, high spatial and temporal resolution. To translate the laboratory innovations into clinical applications, their potential toxicities are highly concerned and have to be evaluated comprehensively both in vitro and in vivo before their clinical applications. In this review, we first summarized the in vivo and in vitro toxicities of the representative inorganic nanoparticles used in biomedical imagings. Then we further discuss the origin of nanotoxicity of inorganic nanomaterials, including ROS generation and oxidative stress, chemical instability, chemical composition, the surface modification, dissolution of nanoparticles to release excess free ions of metals, metal redox state, and left-over chemicals from synthesis, etc. We intend to provide the readers a better understanding of the toxicology aspects of inorganic nanomaterials and knowledge for achieving optimized designs of safer inorganic nanomaterials for clinical applications.     

Screening of organic solvents for bioprocesses using aqueous-organic two-phase systems

The application of conventional organic solvents has been essential in several steps of bioprocesses in order to achieve sufficient economic efficiency. The use of organic solvents is frequently used either to partly or fully replace water in the reaction medium or as a process aid for downstream separation.Nowadays, manufacturers are increasingly requested to avoid and substitute solvents with hazardous potential. Therefore, the solvent selection must account for potential environmental hazards, health and safety problems, in addition to fulfilling the ideal characteristics for application in a process.For the first time, criteria including Environment, Health and Safety (EHS), as well as the technical requirements for reaction and separation have been reviewed, collected and integrated in a single organic solvent screening strategy to be used as a guideline for narrowing down the list of solvents to test experimentally. Additionally, we have also included a solvent selection guide based on the methodology developed in the Innovative Medicines Initiative CHEM21 (IMI CHEM21) project and applied specifically to water-immiscible solvents commonly used in bioprocesses.     

Immobilized Candida antarctica lipase B: Hydration, stripping off and application in ring opening polyester synthesis

This work reviews the stripping off, role of water molecules in activity, and flexibility of immobilized Candida antarctica lipase B (CALB). Employment of CALB in ring opening polyester synthesis emphasizing on a polylactide is discussed in detail. Execution of enzymes in place of inorganic catalysts is the most green alternative for sustainable and environment friendly synthesis of products on an industrial scale. Robust immobilization and consequently performance of enzyme is the essential objective of enzyme application in industry. Water bound to the surface of an enzyme (contact class of water molecules) is inevitable for enzyme performance; it controls enzyme dynamics via flexibility changes and has intensive influence on enzyme activity. The value of pH during immobilization of CALB plays a critical role in fixing the active conformation of an enzyme. Comprehensive selection of support and protocol can develop a robust immobilized enzyme thus enhancing its performance. Organic solvents with a log P value higher than four are more suitable for enzymatic catalysis as these solvents tend to strip away very little of the enzyme surface bound water molecules. Alternatively ionic liquid can work as a more promising reaction media. Covalent immobilization is an exclusively reliable technique to circumvent the leaching of enzymes and to enhance stability. Activated polystyrene nanoparticles can prove to be a practical and economical support for chemical immobilization of CALB. In order to reduce the E-factor for the synthesis of biodegradable polymers; enzymatic ring opening polyester synthesis (eROPS) of cyclic monomers is a more sensible route for polyester synthesis. Synergies obtained from ionic liquids and immobilized enzyme can be much effective eROPS.     

Attributable risk function in the proportional hazards model for censored time-to-event

Time-to-event endpoints are often used in clinical and epidemiological studies to evaluate disease association with hazardous exposures. In the statistical literature of time-to-event analysis, such association is usually measured by the hazard ratio in the proportional hazards model. In public health, it is also of important interest to assess the excess risk attributable to an exposure in a given population. In this article, we extend the notion of 'population attributable fraction' for the binary outcomes to the attributable risk function for the event times in prospective studies. A simple estimator of the time-varying attributable risk function is proposed under the proportional hazards model. Its inference procedures are established. Monte-Carlo simulation studies are conducted to evaluate its validity and performance. The proposed methodology is motivated and demonstrated by the data collected in a multicenter acquired immunodeficiency syndrome (AIDS) cohort study to estimate the attributable risk of human immunodeficiency virus type 1 (HIV-1) infections due to several potential risk factors.     

Analysis of pregnancy-related calls to an occupational hazard hot line.

Since 1980 the Hazard Evaluation System and Information Service has responded to over 11,000 inquiries regarding workplace health hazards. Of 2,424 inquiries in 1986, 593 (24%) concerned hazards to pregnancy. This represents a 17-fold increase since 1981. Most pregnancy-related inquiries were from employees (70%) and health care providers (23%). Referral sources for the employees calls were almost exclusively individual health care providers or institutions that provide health care or health counseling, or both. These data suggest that pregnant employees seek information on their own or from health care providers instead of from employers. Of the inquiries, 80% were for general pregnancy hazard information; 20% involved symptomatic pregnant employees. Most inquiries concerned employment in the services (58%) and manufacturing (26%) sectors. Organic solvents, pesticides, acrylic nail-grooming products, lead, and video display terminals were among the agents about which callers inquired most frequently.     

Potential hazards associated with the consumption of Scombridae fish: Infection and toxicity from raw material and processing

Scombridae fish (tuna, bonito and mackerel) have significant ecological and economic values. They are very appreciated by consumers worldwide for their high-quality flesh and for their high nutritional value. However, consumption of Scombridae fish is potentially hazardous. Indeed, several cases of infections and toxicity linked to the consumption of Scombridae fish as raw, or processed food products have been reported worldwide. In this review, we presented the most common health risks associated with Scombridae fish consumption. Diseases associated with the consumption of these fish are generally infectious or toxic and are caused by biological hazards, such as bacteria, viruses, parasites or chemicals hazards that enter the body through contaminated fish (polycyclic aromatic hydrocarbons, histamine) or by physical contaminants, such as heavy metals. The risks of contamination exist throughout the food chain, from primary production to the preparation of products for consumption.     

Using Nanotechnology for the Substitution of Hazardous Chemical Substances

It is often assumed that nanotechnology (NT) holds the potential to provide a substantial contribution to the solution of various ecological problems, including high consumption of energy and materials and the generation of waste. However, problems surrounding the use and release of hazardous substances remain largely unexplored. For this reason, the Scientific Technical Option Assessment (STOA) Panel of the European Parliament initiated a study on “The Role of Nanotechnology in Chemical Substitution.” The subject and aim of the study was an investigation into preexisting and potential applications of NT that could lead to a reduction in hazardous substances by providing substitutes for them. In terms of method, it was based on electronic searches of the literature, expert interviews, and an expert workshop. This article discusses the results of the project. It focuses on the methodological challenges and the principal problems resulting from a combination of the broad and ill‐defined concept of NT and the specific concept of hazardous substances. The hazardous substances addressed had to be reduced to a manageable number, and the term substitution was understood according to the characteristics of NT and the way in which the latter could reduce the use of hazardous substances. Although several applications of NT were identified that could lead to a considerable reduction in the use of hazardous substances, ambiguities in both the concept of NT and the concept of substitution in relation to NT prevent a comprehensive assessment of the potential of NT in respect to substitution.