Neurotransmitters and Behavioral Alterations Induced by Nickel Exposure.

BACKGROUND: Nickel ions (Ni2+) are a heavy metal with wide industrial uses. Environmental and occupational exposures to Ni are potential risk factors for brain dysfunction and behavioral and neurological symptoms in humans. METHODS: We reviewed the current evidence about neurochemical and behavioral alterations associated with Ni exposure in laboratory animals and humans. RESULTS: Ni2+ exposure can alter (both inhibition and stimulation) dopamine release and inhibit glutamate NMDA receptors. Few reports claim an effect of Ni2+ at the level of GBA and serotonin neurotransmission. At behavioral levels, exposure to Ni2+ in rodents alters motor activity, learning and memory as well as anxiety and depressive-like symptoms. However, no analysis of the dose-dependent relationship has been carried out regarding these effects and the levels of the Ni2+ in the brain, in blood or urine. CONCLUSION: Further research is needed to correlate the concentration of Ni2+ in biological fluids with specific symptoms/deficits. Future studies addressing the impact of Ni2+ under environmental or occupational exposure should consider the administration protocols to find Ni2+ levels similar in the general population or occupationally exposed workers.

Breath biomarkers in toxicology.

Exhaled breath has joined blood and urine as a valuable resource for sampling and analyzing biomarkers in human media for assessing exposure, uptake metabolism, and elimination of toxic chemicals. This article focuses current use of exhaled gas, aerosols, and vapor in human breath, the methods for collection, and ultimately the use of the resulting data. Some advantages of breath are the noninvasive and self-administered nature of collection, the essentially inexhaustible supply, and that breath sampling does not produce potentially infectious waste such as needles, wipes, bandages, and glassware. In contrast to blood and urine, breath samples can be collected on demand in rapid succession and so allow toxicokinetic observations of uptake and elimination in any time frame. Furthermore, new technologies now allow capturing condensed breath vapor directly, or just the aerosol fraction alone, to gain access to inorganic species, lung pH, proteins and protein fragments, cellular DNA, and whole microorganisms from the pulmonary microbiome. Future applications are discussed, especially the use of isotopically labeled probes, non-targeted (discovery) analysis, cellular level toxicity testing, and ultimately assessing "crowd breath" of groups of people and the relation to dose of airborne and other environmental chemicals at the population level.

Experimentally increased temperature and hypoxia affect stability of social hierarchy and metabolism of the Amazonian cichlid Apistogramma agassizii.

The primary goal of this study was to understand how changes in temperature and oxygen could influence social behaviour and aerobic metabolism of the Amazonian dwarf cichlid Apistogramma agassizii. Social hierarchies were established over a period of 96h by observing the social interactions, feeding behaviour and shelter use in groups of four males. In the experimental environment, temperature was increased to 29°C in the high-temperature treatment, and oxygen lowered to 1.0mg·L(-1)O2 in the hypoxia treatment. Fish were maintained at this condition for 96h. The control was maintained at 26°C and 6.6mg·L(-1)O2. After the experimental exposure, metabolism was measured as routine metabolic rate (RMR) and electron transport system (ETS) activity. There was a reduction in hierarchy stability at high-temperature. Aggression changed after environmental changes. Dominant and subdominant fish at high temperatures increased their biting, compared with control-dominant. In contrast, hypoxia-dominant fish decreased their aggressive acts compared with all other fish. Shelter use decreased in control and hypoxic dominant fish. Dominant fish from undisturbed environments eat more than their subordinates. There was a decrease of RMR in fish exposed to the hypoxic environment when compared with control or high-temperature fish, independent of social position. Control-dominant fish had higher RMR than their subordinates. ETS activity increased in fish exposed to high temperatures; however, there was no effect on social rank. Our study reinforces the importance of environmental changes for the maintenance of hierarchies and their characteristics and highlights that most of the changes occur in the dominant position.

Lung Function in Rural Guatemalan Women Before and After a Chimney Stove Intervention to Reduce Wood Smoke Exposure: Results From the Randomized Exposure Study of Pollution Indoors and Respiratory Effects and Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter Study.

BACKGROUND: COPD is the third most frequent cause of death globally, with much of this burden attributable to household biomass smoke exposure in developing countries. As biomass smoke exposure is also associated with cardiovascular disease, lower respiratory infection, lung cancer, and cataracts, it presents an important target for public health intervention. METHODS: Lung function in Guatemalan women exposed to wood smoke from open fires was measured throughout the Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) stove intervention trial and continued during the Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter (CRECER) cohort study. In RESPIRE, early stove households received a chimney woodstove at the beginning of the 18-month trial, and delayed stove households received a stove at trial completion. Personal exposure to wood smoke was assessed with exhaled breath carbon monoxide (CO) and personal CO tubes. Change in lung function between intervention groups and as a function of wood smoke exposure was assessed using random effects models. RESULTS: Of 306 women participating in both studies, acceptable spirometry was collected in 129 early stove and 136 delayed stove households (n = 265), with a mean follow-up of 5.6 years. Despite reduced wood smoke exposures in early stove households, there were no significant differences in any of the measured spirometric variables during the study period (FEV1, FVC, FEV1/FVC ratio, and annual change) after adjustment for confounding. CONCLUSIONS: In these young Guatemalan women, there was no association between lung function and early randomization to a chimney stove or personal wood smoke exposure. Future stove intervention trials should incorporate cleaner stoves, longer follow-up, or potentially susceptible groups to identify meaningful differences in lung function.

Terpenes and terpenoids in chemical sensitivity.

UNLABELLED: CONTEXT : Terpenes and terpenoids are a diverse class of organic compounds produced by a variety of plants, particularly conifers. Chemically sensitive patients can be targeted by terpenes and terpenoids, resulting in a triggering of symptoms and pathology. Often patients cannot clear their symptoms from exposure to chemicals unless terpenes and terpenoids are avoided and neutralized along with chemical avoidance and treatment. OBJECTIVE: This article evaluates the presence, diagnosis, and treatment of terpenes exposure in chemically sensitive patients. DESIGN: A double-blind, placebo-controlled, 2-part study was designed to establish the chemically sensitive state of the patients in part 1, followed by a second set of challenges to determine each patient's concurrent sensitivity to terpenes and terpenoids in part 2. In all of the challenges, normal saline was used as a control. A case report illustrates the history of 1 patient and describes the authors' treatment methods. SETTING: The study was developed and conducted at the Environmental Health Center of Dallas (EHC-D) because the environment within the center is 5 times less polluted than the surrounding environments, as determined by quantitative air analysis and particulate counts. PARTICIPANTS: A total of 45 chemically sensitive patients at EHC-D with odor sensitivity to terpenes. The cohort included 18 males and 27 females, aged 24-62 y.Intervention • Patients were deadapted (4 d) and evaluated in a 5-times-less-polluted environment, which was evaluated using air analysis and particulate counts. After deadaptation, the patients were challenged by inhalation in a controlled, less-polluted glass steel booth inside an environmentally controlled room with an ambient air dose of the toxics in the order of parts per billion (PPB) and parts per million (PPM). These toxics included formaldehyde, pesticide, cigarette smoke, ethanol, phenol, chlorine, new sprint, perfume, and placebo. They were also challenged intradermally with extracts of volatile organic compounds (VOCs), including formaldehyde, orris root, ethanol, phenol, cigarette smoke, chlorine, newsprint, perfume, terpenes, terpenoids, and placebo. OUTCOME MEASURES: Inhaled challenges recorded pulse, blood pressure, peak bronchial flow, and other signs and symptoms 30 min before and at 15-min intervals for 2 h postchallenge. Intradermal challenges recorded wheal size and the provocation of signs and symptoms. RESULTS : Different numbers of patients were tested for each terpenes source because of time-related factors or the cumulative effect of testing, which made patients unable to continue. Of 45 chemically sensitive patients in the study, 43 demonstrated sensitivity to terpenes. CONCLUSIONS: This particular patient group was positive for a number of toxic and nontoxic chemicals provoking their symptoms. This study shows there was a connection between VOCs, other chemicals, and terpenes in chemically sensitive patients in a prospective cohort study. It has also shown the potential for terpenes to exacerbate symptoms of chemical sensitivity. Further research on this topic is recommended.

[The informativeness of indices of the heart rate variability for the identification of the adverse effects of environmental factors on the health of adolescent girls].

There was performed an investigation of informativeness of indices of the heart rate variability at rest and during orthostatic testing in the adolescent girls residing in the industrial town and in the village. The influence of unfa- vorable environmental factors was established to be reflected by the indices of the spectral analysis and cardioin- tervalography. In urban girls there was noted the marked increase of the centralization of heart rhythm control on the background of the increased activity of the sympathetic compartment and the reduction of the influence of the parasympathetic compartment of the autonomous nervous system on the sinus node. In rural adolescent girls the func- tional state of the autonomic nervous system being the optimal is characterized by an adequate response to the active orthostatic test of the parasympathetic and sympathetic compartments with the moderate involvement of mechanisms of the central control of the cardiac rhythm. Results of the study have an important significance for the diagnosis of the early disorders of health in adolescent girls.

In utero and early childhood exposure to arsenic decreases lung function in children.

The lung is a target organ for adverse health outcomes following exposure to As. Several studies have reported a high prevalence of respiratory symptoms and diseases in subjects highly exposed to As through drinking water; however, most studies to date has been performed in exposed adults, with little information on respiratory effects in children. The objective of the study was to evaluate the association between urinary levels of As and its metabolites with lung function in children exposed in utero and in early childhood to high As levels through drinking water. A total of 358 healthy children were included in our study. Individual exposure was assessed based on urinary concentration of inorganic As. Lung function was assessed by spirometry. Participants were exposed since pregnancy until early childhood to an average water As concentration of 152.13 µg l⁻¹. The mean urinary As level registered in the studied subjects was 141.2 µg l⁻¹ and only 16.7% had a urinary concentration below the national concern level. Forced vital capacity was significantly decreased in the studied population and it was negatively associated with the percentage of inorganic As. More than 57% of the subjects had a restrictive spirometric pattern. The urinary As level was higher in those children with restrictive lung patterns when compared with the levels registered in subjects with normal spirometric patterns. Exposure to As through drinking water during in utero and early life was associated with a decrease in forced vital capacity and with a restrictive spirometric pattern in the children evaluated.

Brain responses to olfactory and trigeminal exposure in idiopathic environmental illness (IEI) attributed to smells -- an fMRI study.

OBJECTIVE: Idiopathic environmental intolerance (IEI) to smells is a prevalent medically unexplained illness. Sufferers attribute severe symptoms to low doses of non-toxic chemicals. Despite the label, IEI is not characterized by acute chemical senses. Theoretical models suggest that sensitized responses in the limbic system of the brain constitute an important mechanism behind the symptoms. The aim was to investigate whether and how brain reactions to low-levels of olfactory and trigeminal stimuli differ in individuals with and without IEI. METHODS: Brain responses to intranasally delivered isoamyl acetate and carbon dioxide were assessed in 25 women with IEI and 26 non-ill controls using functional magnetic resonance imaging. RESULTS: The IEI group had higher blood-oxygenated-level-dependent (BOLD) signal than controls in the thalamus and a number of, mainly, parietal areas, and lower BOLD signal in the superior frontal gyrus. The IEI group did not rate the exposures as more intense than the control group did, and there were no BOLD signal differences between groups in the piriform cortex or olfactory regions of the orbitofrontal cortex. CONCLUSIONS: The IEI reactions were not characterized by hyper-responsiveness in sensory areas. The results can be interpreted as a limbic hyperreactivity and speculatively as an inability to inhibit salient external stimuli.

Air pollution exposure and lung function in highly exposed subjects in Beijing, China: a repeated-measure study.

BACKGROUND: Exposure to ambient particulate matter (PM) has been associated with reduced lung function. Elemental components of PM have been suggested to have critical roles in PM toxicity, but their contribution to respiratory effects remains under-investigated. We evaluated the effects of traffic-related PM(2.5) and its elemental components on lung function in two highly exposed groups of healthy adults in Beijing, China. METHODS: The Beijing Truck Driver Air Pollution Study (BTDAS) included 60 truck drivers and 60 office workers evaluated in 2008. On two days separated by 1-2 weeks, we measured lung function at the end of the work day, personal PM(2.5), and nine elemental components of PM(2.5) during eight hours of work, i.e., elemental carbon (EC), potassium (K), sulfur (S), iron (Fe), silicon (Si), aluminum (Al), zinc (Zn), calcium (Ca), and titanium (Ti). We used covariate-adjusted mixed-effects models including PM(2.5) as a covariate to estimate the percentage change in lung function associated with an inter-quartile range (IQR) exposure increase. RESULTS: The two groups had high and overlapping exposure distributions with mean personal PM(2.5) of 94.6 µg/m³ (IQR: 48.5-126.6) in office workers and 126.8 µg/m³ (IQR: 73.9-160.5) in truck drivers. The distributions of the nine elements showed group-specific profiles and generally higher levels in truck drivers. In all subjects combined, forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) did not significantly correlate with PM(2.5). However, FEV1 showed negative associations with concentrations of four elements: Si (-3.07%, 95% CI: -5.00; -1.11, IQR: 1.54), Al (-2.88%, 95% CI: -4.91; -0.81, IQR: 0.86), Ca (-1.86%, 95% CI: -2.95; -0.76, IQR: 1.33), and Ti (-2.58%, 95% CI: -4.44; -0.68, IQR: 0.03), and FVC showed negative associations with concentrations of three elements: Si (-3.23%, 95% CI: -5.61; -0.79), Al (-3.26%, 95% CI: -5.73; -0.72), and Ca (-1.86%, 95% CI: -3.23; -0.47). In stratified analysis, Si, Al, Ca, and Ti showed associations with lung function only among truck drivers, and no significant association among office workers. CONCLUSION: Selected elemental components of PM(2.5) showed effects on lung function that were not found in analyses of particle levels alone.

Interactions between zinc deficiency and environmental enteropathy in developing countries.

Zinc deficiency affects one-fifth of the world's population and leads to substantial morbidity and mortality. Environmental enteropathy (EE), a subclinical pathology of altered intestinal morphology and function, is almost universal among people living in developing countries and affects long-term growth and health. This review explores the overlapping nature of these 2 conditions and presents evidence for their interaction. EE leads to impaired zinc homeostasis, predominantly due to reduced absorptive capacity arising from disturbed intestinal architecture, and zinc deficiency exacerbates several of the proposed pathways that underlie EE, including intestinal permeability, enteric infection, and chronic inflammation. Ongoing zinc deficiency likely perpetuates the adverse outcomes of EE by worsening malabsorption, reducing intestinal mucosal immune responses, and exacerbating systemic inflammation. Although the etiology of EE is predominantly environmental, zinc deficiency may also have a role in its pathogenesis. Given the impact of both EE and zinc deficiency on morbidity and mortality in developing countries, better understanding the relation between these 2 conditions may be critical for developing combined interventions to improve child health.

Environmental origins of congenital heart disease: the heart-placenta connection.

Although the mammalian embryo is well protected in the uterus, environmental chemicals, drugs, and maternal nutritional imbalances can interfere with regulatory pathways directing placental and embryonic development early in gestation. Embryonic cells are most susceptible to environmental influences during cellular specification and differentiation stages. Because biochemical differentiation precedes morphological outcome often by days, the period of susceptibility to environmental chemicals expectedly precedes visible morphogenic effects. The cellular mechanisms by which drugs and other environmental factors disrupt embryonic development and induce cardiac abnormalities have remained undefined.

[Assessment of actual nutrition of Arctic migrants sympathoadrenal and the activity of the sympathoadrenal system].

The complex of extreme factors of the Arctic and unbalanced diet have an adverse effect on a human and alter the functional activity of his sympathoadrenal system. Representative sample of migrants in the Arctic was examined to study the structure of nutrition as a factor of influence on the activity of the sympathoadrenal system. The actual nutrition of migrants in the Arctic plays a role of a stressing factor that increases the tone of the sympathoadrenal system.

[Assessment of adaptive response on environmental risk factors: methodological aspects].

The response to adverse environmental factors, manifesting itself in the reduction of bodily reserves, deterioration of adaptive state and immune status is an integrated indicator used for measuring these adverse effects. A study of the dependence of autonomic balance on gender, age and environmental risks factors has revealed a pronounced sympathicotonia among 64.4-91.5% children and stress of regulatory system among 60.5% cases. The activity of sympathetic nervous system increases with age, especially among men. The severity of disorders depends on the level of emotional stress. The study has found a connection between the general non-specific adaptive response of tumors and cardiovascular diseases.

Genetics of hearing loss: where are we standing now?

Hearing loss (HL) is the most common sensory impairment and is caused by a broad range of inherited to environmental causes. Inherited HL consists 50-60% of all HL cases. The inherited form of HL is further classified to different categories. More than 300 syndromes and 40 genes have been identified to result in different levels of HL. Although several diagnostic or screening tests have been developed, yet there are controversies around their use.

Windows of lead exposure sensitivity, attained height, and body mass index at 48 months.

OBJECTIVE: To examine longitudinal associations of prenatal, infancy, and early childhood lead exposure during sensitive periods with height and body mass index (BMI). STUDY DESIGN: A total of 773 participants were recruited between 1994 and 2005 in Mexico City. Lead exposure history categories were constructed for the prenatal period (maternal patellar lead concentration) and for infancy and childhood (mean child blood lead concentration at birth to 24 months and 30-48 months, respectively). Linear regression models were used to study lead exposure history with height and BMI at 48 months. RESULTS: Mean height at age 48 months was significantly lower in children with a blood lead level exceeding the median during infancy (-0.84 cm; 95% CI, -1.42 to -0.25) than in children with a level below the median. Prenatal lead exposure was not associated with height at 48 months. Results for attained BMI generally trended in the same direction as for height. CONCLUSION: Our findings suggest an effect of lead exposure early in life on height attainment at 48 months, with the exposure window of greatest sensitivity in infancy.

Acoustic stapedius muscle reflex in mercury-exposed Andean children and adults.

CONCLUSION: The results suggested mercury (Hg)-induced anomalies in the brainstem-mediated acoustic stapedius muscle reflex in children. OBJECTIVES: Hg exposure has been associated with hearing impairment and brainstem anomalies. Acoustic stapedius reflex (ASR) thresholds, growth functions, decay/adaptation times, and behavioral auditory thresholds were used to screen Andean children and adults for Hg-induced auditory brainstem and facial nerve impairment. METHODS: Fifty-one participants, which included 22 children (aged 6-17 years) and 29 adults (aged 19-83 years) living in gold mining areas of Ecuador where Hg is widely used in amalgamation, were screened using ASR immittance procedures. RESULTS: Mean blood mercury (HgB) level in the children was 15.6 µg/L (SD, 21.3; median, 7 µg/L; range, 2.0-89 µg/L), and in the adults 8.5 µg/L (SD, 7.1; median, 6 µg/L; range, 2.0-32 µg/L). Mean contralateral ASR thresholds (ASRT) for the screening frequency of 2000 Hz in the children (39 ears) was 92.9 dB HL (SD, 6.1; range, 80-105 dB HL), and in the adults (53 ears) 90.0 dB HL (SD, 6.4; range, 65-105 dB HL). The ASRT in the children increased significantly with HgB level (rho = 0.433; p = 0.008).

[The health condition of workers of enterprises with different level of ecological pollution].

The article considers the functional conditions of organism of workers depending on the location of enterprise. The dependencies of values of indicators of functional conditions and health on different enterprises from ecological pollution of their locations are established The subjective opinion of workers concerning their health conditions and capacity for work was found out. The relationship between workers' morbidity and percentage of persons systematically engaged in physical training is determined. The prospective decrease of morbidity of workers of enterprises was calculated for case of 100% coverage of all working persons with physical training

Preliminary report on aerotoxic syndrome (AS) and the need for diagnostic neurophysiological tests.

Researchers have found, in studies carried out over several years, that many passengers and crew, following their recent flights in commercial jet aeroplanes, have become unwell, with a range of symptoms in common. This condition, which has not yet been officially recognised, is called Aerotoxic Syndrome (AS). It seems to be caused, primarily, by neurotoxic organophosphates contaminating the air circulating in jet cabins. Patients with such symptoms may visit their GPs, who then arrange diagnostic tests. Some of their symptoms fall within the jurisdiction of diagnostic neurophysiological investigations, but neurophysiology practitioners may be unaware of this syndrome. Until AS is officially recognised as an illness, and guidelines for diagnostic procedures established, patients requiring specific investigations may not be appropriately referred, or tests may be performed unnecessarily. This report seeks to stimulate debate within the field, and facilitate studies, if needed, to help define the diagnostic criteria.

Neurologic and neuropsychiatric syndrome features of mold and mycotoxin exposure.

Human exposure to molds, mycotoxins, and water-damaged buildings can cause neurologic and neuropsychiatric signs and symptoms. Many of these clinical features can partly mimic or be similar to classic neurologic disorders including pain syndromes, movement disorders, delirium, dementia, and disorders of balance and coordination. In this article, the author delineates the signs and symptoms of a syndrome precipitated by mold and mycotoxin exposure and contrasts and separates these findings neurodiagnostically from known neurologic diseases. This clinical process is designed to further the scientific exploration of the underlying neuropathophysiologic processes and to promote better understanding of effects of mold/mycotoxin/water-damaged buildings on the human nervous system and diseases of the nervous system. It is clear that mycotoxins can affect sensitive individuals, and possibly accelerate underlying neurologic/pathologic processes, but it is crucial to separate known neurologic and neuropsychiatric disorders from mycotoxin effects in order to study it properly.