Airborne Chemicals Research Articles

Metal Impregnated Silica-Carbon Materials from Rice Husk: A Versatile Sorbent for Toxic Organics and Inorganics in Water and Air

Carbon bearing materials derived from rice husk (RH) have long been recognized as sorbents for diverse chemicals – both organic and inorganic. This work presents an overview of studies demonstrating a single step process of carbonization of chemically pretreated RH to produce metal impregnated silica-carbon char designated as silicarbon materials that can be utilized in sorbing out water-borne organic and inorganic hazardous substances (such as phenol, hexavalent chromium, fluoride, and arsenic) and air-borne volatile organic chemicals (such as acetone, chloroform, benzene, and pyridine). The metal-impregnated silicarbon solids derived from RH appear to constitute renewable, low-cost, user-friendly, and efficient materials for control systems for indoor air contamination and for industrial as well as non-industrial hazardous aqueous pollution.

Living with a Chemically Sensitive Wife: A “We” Situation

Objectives. Multiple chemical sensitivity (MCS) is a medically unexplained and socially disabling disorder characterized by negative health effects attributed to exposure to common airborne chemicals. How spouses of chemically sensitive women experience and cope with their partners illness has not been described previously. Methods. This study presents data from three semistructured focus group interviews with a selective sample of 13 men whose spouses had MCS. Data was analyzed using systematic text condensation with a special focus on coping. Results. The informants expressed a great concern for their wives and described their role in the relationship as that of a “watchdog”, always alert and ready to protect. A considerable amount of time and effort was thus given to avoid symptom-eliciting chemicals to prevent illness. Informing guests of restrictions and observing neighbours’ daily routines were common occurrences. Masks, installation of additional air filters in cars and houses, and other protective measures had necessitated several participants taking on extra work to alleviate the economic burden. The wives' illness had thus become a “we” situation. Discussion. In conclusion, MCS was perceived as a “we” situation and may thus impose considerable strain on the relationship and the family as a whole.

Monument 14 (review)

Reviewed by: Monument 14 Elizabeth Bush Laybourne, Emmy . Monument 14. Feiwel, 2012. [304p]. ISBN 978-0-312-56903-7 $16.99 Reviewed from galleys R Gr. 8-12. When a vicious hailstorm sends traffic into deadly chaos, a quick-thinking school-bus driver brings the fourteen kids in her charge to safety by crashing directly into the Greenway megastore in Monument, Colorado. While she goes off for help, the students, who range from kindergarten through high school, realize they could be a lot worse off. National Connectivity, the national wireless service in 2024, is down, but there's electricity, plenty of food (one girl knows how to work the pizza oven), and the comfort of knowing they are surrounded by anything they could need to ride out bad weather. No self-respecting survival-story author, though, will let the kids off that easily. The hail was triggered by a volcanic eruption, which caused a tsunami and earthquakes, which released chemical weapons under development at [End Page 29] the Colorado NORAD site. (Now, that's more like it.) While narrator Dean lusts after Astrid, his computer-geek brother rigs an old-school television to monitor the news, several kids have reactions to the airborne chemicals, the football stars get stoned (handy, that pharmacy), desperate outsiders try to break in, little kids variously wallow in junk food or panic, the sophomore girl tries to seduce the stoners, and just about anything you think might happen does. The star of this outing is probably the megastore itself, and much of the reader's pleasure derives from imagining just how you'd deploy the endless supply of stuff at hand for survival and pure hedonism. Laybourne keeps most of her cast alive but splits them into evacuees and store-dwellers by tale's end, which surely means there's more cinematic mayhem to come. Pass the five-pound bag of corn chips. Copyright © 2012 The Board of Trustees of the University of Illinois

Mindfulness‐based cognitive therapy to treat multiple chemical sensitivities: A randomized pilot trial

Multiple chemical sensitivities (MCS) is a medically unexplained and socially disabling disorder characterized by negative health effects attributed to exposure to common airborne chemicals. Currently, there is no evidence-based treatment. The objectives of the study were to assess the feasibility of an 8-week mindfulness-based cognitive therapy program (MBCT) for adults with MCS and to evaluate possible effects on psychological distress and illness perception. The study design was a randomized clinical trial. The MBCT programme comprised 8 weekly sessions of 2½ hours. Forty-two adults were screened for eligibility and 37 were included. Mean age of the participants was 51.6 years, 35 (94.6%) were female and 21 (56.8%) were unemployed. Measures of psychological distress and illness perceptions were assessed at baseline, 4 weeks, 8 weeks and at 3 months follow-up. No significant differences in effect measures were found between the groups. However, those who completed the MBCT program generally reported benefiting in terms of improved coping strategies and sleep quality. The positive verbal feedback from the participants in the MBCT group suggests that a larger randomized clinical trial on the effect of MBCT for MCS could be considered.

Screening Criteria for Long-Range Transport Potential of Organic Substances in Water

Screening of long-range transport potential (LRTP) of organic chemicals in water requires the development of criteria in analogy to the existing LRTP criteria for airborne chemicals. According to the Stockholm Convention, compounds mainly partitioning into air are assumed to be prone to LRTP if they have a half-life in air of more than two days. Using mean flow velocities of European rivers (0.7-1 m/s) and of ocean currents running into the Arctic Ocean (0.28-0.9 m/s), we derived corresponding half-life criteria for freshwater and seawater (10 days and 90 days, respectively). Next, we calculated the characteristic travel distance (CTD) of several thousand chemicals from the Canadian Domestic Substances List (DSL) and all current POPs using the multimedia model ELPOS. This shows that the CTD in water dominates the CTD in air only for chemicals that are characterized by a large half-life in water and a low air-water partition coefficient (about 38% of the nonionic organic substances selected from the DSL). In particular, there are substances that are not classified as persistent compounds in water but exhibit higher CTDs for transport in water than for transport in air. Finally, we evaluated whether the LRTP boundary derived from POP reference chemicals has to be revised if LRTP in water is included and found that this boundary can be applied to all organic chemicals regardless of their transport in air or water.

Effects of pyridine inhalation exposure on olfactory epithelium in mice

Olfactory neurons in the nasal mucosa have the capacity to regenerate continuously along the lifespan by neurogenesis processes starting with progenitor cells close to the basal lamina. The cellular turnover into olfactory neuroepithelium may be modified by environmental stimuli insofar as nasal mucosa is directly in contact with airborne chemicals. However, few studies have been focused on selective changes, especially those concerning mature olfactory neurons and basal cells during specific inhalation exposure. Among chemicals, solvents are known to induce changes in smell abilities and concomitant histological and cellular modifications related to the type of molecule, concentration and time of exposure. This study was designed to characterize smell sensitivity (using behavioral tests) and immunohistochemical effects on olfactory neuroepithelium induced by pyridine exposure in mice. Olfactory marker protein (OMP) and proliferating cell nuclear antigen (PCNA) were used to characterize respectively mature olfactory neurons and basal cells. Results showed that inhalation exposure to pyridine had no impact on smell sensitivity whatever the concentration used and the time of exposure. These findings were in agreement with immunohistochemical measurements showing the same cellular kinetic whatever the condition of exposition to pyridine. Indeed, OMP-positive cells increased and PCNA-positive cells decreased as early as the beginning of exposure and cell amounts remained stable at this level until the end of exposure. These findings suggest that pyridine could have the property to rapidly activate a cellular turnover from basal cell progenitors. Rather than toxic effects, the present findings suggest that the metabolites of pyridine might have cell cycle activation properties.

Mate location and antennal morphology in the praying mantidHierodula majuscula

AbstractMany sensory modes can be exploited to determine the location of potential mates. In insects, long‐distance location primarily involves chemical or acoustic cues, whereas short‐distance communication mainly utilises visual or tactile cues. The structural complexity of the environment may influence the transmission of information, and therefore, it is common to see multiple sensory modes employed to increase the likelihood of accurate mate location. Praying mantids are known to use airborne chemicals for long‐distance location and visual cues in close proximity. This study examined which types of cues are used for mate location in an unstudied species,Hierodula majuscula, from Queensland, Australia. The timing of female pheromone emission during ‘calling’ periods reached a peak at 3:00 h, with the majority of females assuming a calling posture at this time. Scanning electron microscopy was used to confirm the presence of basiconic sensilla (used for chemical reception) on male antennae, and males successfully responded to female chemical cues and subsequently located potential mates. Males were not as successful at finding females when restricted to using visual cues.

New insights into an ancient insect nose: The olfactory pathway of Lepismachilis y-signata (Archaeognatha: Machilidae)

Hexapods most likely derived from an aquatic ancestor, which they shared with crustaceans. During the transition from water to land, their sensory systems had to face the new physiological demands that terrestrial conditions impose. This process also concerns the sense of smell and, more specifically, detection of volatile, air-borne chemicals. In insects, olfaction plays an important role in orientation, mating choice, and food and host finding behavior. The first integration center of odor information in the insect brain is the antennal lobe, which is targeted by the afferents from olfactory sensory neurons on the antennae. Within the antennal lobe of most pterygote insects, spherical substructures called olfactory glomeruli are present. In order to gain insights into the evolution of the structure of the central olfactory pathway in insects, we analyzed a representative of the wingless Archaeognatha or jumping bristletails, using immunocytochemistry, antennal backfills and histological section series combined with 3D reconstruction. In the deutocerebrum of Lepismachilis y-signata, we found three different neuropil regions. Two of them show a glomerular organization, but these glomeruli differ in their shape from those in all other insect groups. The connection of the glomerular neuropils to higher brain centers remains unclear and mushroom bodies are absent as reported from other archaeognathan species. We discuss the evolutionary implications of these findings.

Transition from marine to terrestrial ecologies: Changes in olfactory and tritocerebral neuropils in land-living isopods

In addition to the ancestors of insects, representatives of five lineages of crustaceans have colonized land. Whereas insects have evolved sensilla that are specialized to allow the detection of airborne odors and have evolved olfactory sensory neurons that recognize specific airborne ligands, there is so far little evidence for aerial olfaction in terrestrial crustaceans. Here we ask the question whether terrestrial Isopoda have evolved the neuronal substrate for the problem of detecting far-field airborne chemicals. We show that conquest of land of Isopoda has been accompanied by a radical diminution of their first antennae and a concomitant loss of their deutocerebral olfactory lobes and olfactory computational networks. In terrestrial isopods, but not their marine cousins, tritocerebral neuropils serving the second antenna have evolved radical modifications. These include a complete loss of the malacostracan pattern of somatotopic representation, the evolution in some species of amorphous lobes and in others lobes equipped with microglomeruli, and yet in others the evolution of partitioned neuropils that suggest modality-specific segregation of second antenna inputs. Evidence suggests that Isopoda have evolved, and are in the process of evolving, several novel solutions to chemical perception on land and in air.

A Method for Computing the Damage Level Due to the Exposure to an Airborne Chemical with a Time‐Varying Concentration

The calculation of damage level due to the exposure to a toxic cloud is usually not included in most popular software, or it is included using techniques that do not take into account the variation in concentration over a period of time. In this work, a method is introduced for calculating the temporal evolution of the potential damage level and to obtain a more precise and descriptive estimation of this level. The proposed goal is: to estimate the maximum and minimum damage level experienced by a population due to the exposure to an airborne chemical with a time-varying concentration; to be able to assess the damage level experienced in a progressive way, as the exposure to the airborne chemical occurs. The method relies on transformations of time-concentration pairs on a continuum of damage level curves based on the available guideline levels, obtaining maximum and minimum approximations of the expected damage level for any exposure duration. Consequently, applying this method to transport model output data and demographic information, damage evolution in relation to time and space can be predicted, as well as its effect on the local population, which enables the determination of threat zones. The comparison between the proposed method and the current (Spanish and ALOHA) ones showed that the former can offer a more precise estimation and a more descriptive approach of the potential damage level. This method can be used by atmospheric dispersion models to compute damage level and graphically display the regions exposed to each guideline level on area maps.

The association between idiopathic environmental intolerance and psychological distress, and the influence of social support and recent major life events

Idiopathic environmental intolerance (IEI) is a disorder characterized by non-specific symptoms attributed to common airborne chemicals. Increasing evidence points to an association between IEI and symptoms of psychological distress. However, whether other risk factors influence this association has not been clarified. The objective of this study was to examine the association between psychological distress and IEI and to determine whether the association is confounded by social support and major life events. Data were collected by postal questionnaires; other results from the study have been published previously in this journal. The study included participants from a general population-based study who had reported symptoms of chemical sensitivities (n = 787) and two patient groups. The first patient group (n = 101) included individuals who had contacted the Danish Research Centre for Chemical Sensitivities, and the second included individuals who had been diagnosed with environmental intolerance (n = 136). Multiple, hierarchical linear regression analyses were conducted with four IEI-related domains, i.e., mucosal and CNS symptoms, chemical intolerances and social consequences, as the dependent variables, and psychological distress, social support and major life events as the independent variables. Our study confirmed positive and statistically significant associations between psychological distress and IEI. The associations remained statistically significant after adjusting for major life events and social support. The results suggest that the association between IEI and psychological distress cannot be explained by known risk factors. More studies, including longitudinal studies, are needed to determine the role of psychological distress in the development and course of IEI.

Non-allergic cutaneous reactions in airborne chemical sensitivity – A population based study

Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.

Use of reference chemicals to determine passive uptake rates of common indoor air VOCs by collocation deployment of active and passive samplers

Passive samplers have become more popular in their application in the measurement of airborne chemicals. For volatile organic compounds, the rate of a chemical's diffusivity is a determining factor in the quantity of the chemical being collected for a given passive sampler. While uptake rate of a chemical in the passive sampler can be determined either by collocation deployment of both active and passive samplers or use of controlled facilities such as environmental chambers, a new approach without a need for accurate active flow rate in the collocation experiment was demonstrated in this study. This approach uses chemicals of known uptake rates as references to calculate the actual flow rate of the active sampling in the collocation experiment. The active sampling rate in turn can be used in the determination of the uptake rates of all other chemicals present in the passive samplers. The advantage of such approach is the elimination of the errors in actual active sampling rate associated with low flow employed in the collocation experiment. Using this approach, passive uptake rates of more than 80 volatile organic compounds commonly present in indoor air were determined. These experimentally determined uptake rates correlate well with air diffusivity of the chemicals, indicating the regression equation describing such correlation might be useful in predicting the uptake rates of other volatile organic chemicals in indoor air based on their air diffusivity.

ChemInform Abstract: Troubleshooting Methods for Toxicity Testing of Airborne Chemicals in vitro

AbstractReview: 149 refs.

A Comparative Study of Snake and Lizard Tongue-flicking, with an Evolutionary Hypothesis

Many lizards and all snakes flick their tongues. It is known that this unique behavioral pattern serves to collect airborne and substrate chemicals which give the animal information via Jacobson's Organ about the location of food, conspecifics, and possibly other environmental factors. However, a comparative topographic analysis of tongue movements in squamate reptiles is lacking, and it might shed light on the evolution of this behavior. In this study, a survey was made of the lizards and snakes which tongue-flick. Observations and films were made of 25 lizard species representing 10 families and 30 snake species representing 5 families. The information from observations and film analyses of representative species was used to hypothesize the steps of the evolution of tongue-flicking from the simple downward extensions of primitive lizards to the complex multiple oscillations of snakes.

Responses to odors in occupational environments

There is mounting evidence that the presence of airborne chemicals that produce odor and irritation can be a significant impediment to a productive and healthy workforce, even among individuals without chemical sensitivity. Studies investigating odor and irritant-induced symptoms in occupational environments suggest that poor indoor air quality, coupled with psychosocial factors such as the work environment, personality and stress, can lead to the development of building-related complaints and exacerbate chemical intolerance and symptoms. The practice of introducing pleasant odors in the workplace to improve productivity and mood is not well supported by current research. Managing the response to odors and irritants in the workplace is critical to maintaining the health and well being of workers. There is a critical need for regulatory organizations in the United States and elsewhere to harmonize guidelines for occupational exposure limits. In addition, management must engage in risk communication and education of workers in order to ensure that misperception of risk from odors does not lead to illness and loss of well being.

Development and Demonstration of a Method to Evaluate Bio-Sampling Strategies Using Building Simulation and Sample Planning Software.

In an effort to validate and demonstrate response and recovery sampling approaches and technologies, the U.S. Department of Homeland Security (DHS), along with several other agencies, have simulated a biothreat agent release within a facility at Idaho National Laboratory (INL) on two separate occasions in the fall of 2007 and the fall of 2008. Because these events constitute only two realizations of many possible scenarios, increased understanding of sampling strategies can be obtained by virtually examining a wide variety of release and dispersion scenarios using computer simulations. This research effort demonstrates the use of two software tools, CONTAM, developed by the National Institute of Standards and Technology (NIST), and Visual Sample Plan (VSP), developed by Pacific Northwest National Laboratory (PNNL). The CONTAM modeling software was used to virtually contaminate a model of the INL test building under various release and dissemination scenarios as well as a range of building design and operation parameters. The results of these CONTAM simulations were then used to investigate the relevance and performance of various sampling strategies using VSP. One of the fundamental outcomes of this project was the demonstration of how CONTAM and VSP can be used together to effectively develop sampling plans to support the various stages of response to an airborne chemical, biological, radiological, or nuclear event. Following such an event (or prior to an event), incident details and the conceptual site model could be used to create an ensemble of CONTAM simulations which model contaminant dispersion within a building. These predictions could then be used to identify priority area zones within the building and then sampling designs and strategies could be developed based on those zones.

Troubleshooting methods for toxicity testing of airborne chemicals in vitro

Toxicology studies of adverse effects induced by inhaled chemicals are technically challenging, due to the requirement of highly controlled experimental conditions needed to achieve reproducible and comparable results. Therefore, many considerations must be fulfilled before adopting in vitro bioassay test systems for toxicity screening of airborne materials. However, recent methodological and technical breakthroughs of in vitro methods have the potential to fulfil the essential requirements of toxicity testing for airborne chemicals. Technology has now become available that allows cells to be cultured on permeable microporous membranes in transwell or snapwell inserts providing a very close contact between target cells and test atmospheres to study the cellular interactions caused by airborne chemical exposures without any interfering culture medium. Using a direct exposure technique at the air–liquid interface, target cells can be continuously exposed to airborne chemicals on their apical side, while being nourished from their basolateral side. Test atmospheres with different physicochemical characteristics such as gases, vapours, solid and liquid aerosols and more recently nanoaerosols, can be delivered into human target cells using static and/or direct dynamic exposure methods. Therefore, toxicological risk assessments of airborne chemicals and even complex atmospheres can be achieved using in vitro test methods in parallel with real-time air monitoring techniques to fulfil the general regulatory requirements of newly developed chemical or pharmaceutical products with the potential for inhalational exposure. In this review current toxicological methods for toxicity testing of inhaled chemicals are presented. Further, to demonstrate the potential application of in vitro methods for studying inhalation toxicity, more advanced exposure techniques developed for toxicity screening of airborne chemicals are discussed.

4162 Sores lips during chemotherapy – a “Cinderella” symptom

1.1. Cases of three patients suffering from cheilitis glandularis apostematosa are presented.2.2. This chronic condition consists of a syndrome of (a) a disfiguring enlargement and ectropion of the lower lip, with certain changes in both the epithelium and the lamina propria of the mucosa of the vermilion zone; (b) a hyperplasia of the labial mucous glands; and (c) an enlargement and inflammation of the excretory ducts of these glands.3.3. Case histories and clinical and histologic examinations seem to indicate that this anomaly is due primarily to chronic chapping, scarring, and subsequent eversion of the lower lip. The ectropion, in turn, is followed by irritation of the exposed vestibular lip mucosa from the drying effect of the air, from actinic rays, air-borne chemicals, and, probably, the repeated contact of this tissue with saliva saturated with tobacco juice.4.4. Roentgen therapy and excision of the lesion have been advocated in the treatment of this condition,8 but no consistently successful therapy is known.13 In view of the absence of any complaint on the part of our patients, we recommended to them the use of a good lip pomade and asked them to stop using tobacco.

Hygroreception in olfactometer studies

Abstract In olfactometric studies, a technique used to measure insect behavioural bias towards airborne chemicals, many of the factors that could affect the bioassay outcome other than the volatiles themselves are carefully controlled (e.g. lighting conditions, temperature, spatial position, physiological state of the insects, time of day when the bioassay is performed) but one factor, namely humidity, is overlooked frequently when studying responses to plant volatiles. Many insect species respond positively and negatively to changes in humidity and, during bioassays, differences arising from odour choices with different water vapour release rates might have confounding effects versus the original intent of the behavioural study. The present study aims to assess the effect of different substrates on the water vapour content of air in an olfactometer‐like set‐up. The results show that airflow humidity is affected by the odour source used in the olfactometer air flow. In addition, the response of the aphid parasitoid Aphidius colemani Viereck (Hymenoptera: Aphidiidae) is studied towards different humidities and plant material in an olfactometer. The present study suggests that humidity needs to be controlled in olfactometric studies.