EPA Takes Action Against Harmful "Forever Chemicals" in the US Water Supply.

This Medical News article discusses new EPA advisories for a class of synthetic chemical compounds known as PFAS, which are ubiquitous in the environment and in humans, as well as new National Academies guidance on expanded testing for exposure.

Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists.

The Earth's mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists' education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.

Incidence, mortality and survival in malignant pleural mesothelioma before and after asbestos in Denmark, Finland, Norway and Sweden.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare but fatal cancer, which is largely caused by exposure to asbestos. Reliable information about the incidence of MPM prior the influence of asbestos is lacking. The nationwide regional incidence trends for MPM remain poorly characterized. We use nationwide MPM data for Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE) to assess incidence, mortality and survival trends for MPM in these countries. METHODS: We use the NORDCAN database for the analyses: incidence data were available from 1943 in DK, 1953 in FI and NO and 1958 in SE, through 2016. Survival data were available from 1967 through 2016. World standard population was used in age standardization. RESULTS: The lowest incidence that we recorded for MPM was 0.02/100,000 for NO women and 0.05/100,000 for FI men in 1953-57, marking the incidence before the influence of asbestos. The highest rate of 1.9/100,000 was recorded for DK in 1997. Female incidence was much lower than male incidence. In each country, the male incidence trend for MPM culminated, first in SE around 1990. The regional incidence trends matched with earlier asbestos-related industrial activity, shipbuilding in FI and SE, cement manufacturing and shipbuilding in DK and seafaring in NO. Relative 1-year survival increased from about 20 to 50% but 5-year survival remained at or below 10%. CONCLUSION: In the Nordic countries, the male incidence trends for MPM climaxed and started to decrease, indicating that the prevention of exposure was beneficial. Survival in MPM has improved for both sexes but long-term survival remains dismal.

Chloro-s-triazines-toxicokinetic, Toxicodynamic, Human Exposure, and Regulatory Considerations.

Chloro-s-triazines-atrazine, cyanazine, propazine, simazine, and terbuthylazine-are structurally similar herbicides, differing only in specific s-triazine4-and 6-N alkyl substituents. It is generally regarded that their toxicokinetics, such as, metabolic pathways, biological effects and toxicities, also share more similar features than the differences. Consequently, it is useful to compare their characteristics to potentially find useful structure-activity relationships or other similarities or differences regarding different active compounds, their metabolites, and biological effects including toxic outcomes. The ultimate goal of these exercises is to apply the summarized knowledge-as far as it is possible regarding a patchy and often inadequate database-to cross the in vitro-in vivo and animal-human borders and integrate the available data to enhance toxicological risk assessment for the benefit of humans and ecosystems.

Inhalation cancer risk assessment for environmental exposure to hexavalent chromium: Comparison of margin-of-exposure and linear extrapolation approaches.

Hexavalent chromium [Cr(VI)] exists in the ambient air at low concentrations (average upperbound ~0.1 ng/m3) yet airborne concentrations typically exceed EPA's Regional Screening Level for residential exposure (0.012 ng/m3) and other similar benchmarks, which assume a mutagenic mode of action (MOA) and use low-dose linear risk assessment models. We reviewed Cr(VI) inhalation unit risk estimates developed by researchers and regulatory agencies for environmental and occupational exposures and the underlying epidemiologic data, updated a previously published MOA analysis, and conducted dose-response modeling of rodent carcinogenicity data to evaluate the need for alternative exposure-response data and risk assessment approaches. Current research supports the role of non-mutagenic key events in the MOA, with growing evidence for epigenetic modifiers. Animal data show a weak carcinogenic response, even at cytotoxic exposures, and highlight the uncertainties associated with the current epidemiological data used in risk assessment. Points of departure from occupational and animal studies were used to determine margins of exposure (MOEs). MOEs range from 1.5 E+3 to 3.3 E+6 with a median of 5 E+5, indicating that current environmental exposures to Cr(VI) in ambient air should be considered of low concern. In this comprehensive review, the divergent results from default linear and MOE assessments support the need for more relevant and robust epidemiologic data, additional mechanistic studies, and refined risk assessment strategies.

Blood lead levels in low-income and middle-income countries: a systematic review.

BACKGROUND: Since the global phase-out of leaded petrol, reports have suggested that lead exposure remains substantial or is increasing in some low-income and middle-income countries (LMICs). However, few studies have attempted to systematically assess blood lead levels over the full range of LMICs. We aimed to describe values for blood lead level in LMICs. METHODS: In this systematic review, we searched PubMed for studies published between Jan 1, 2010, and Oct 31, 2019, that reported blood lead levels in the 137 countries in World Bank LMIC groupings. Studies were reviewed for inclusion if they contained blood lead level data from human populations residing in any given country; comprised at least 30 participants; presented blood lead level data derived from venous, capillary, or umbilical cord samples of whole blood; had data that were collected after Dec 31, 2004; and were published in English. Data on blood lead level were extracted and pooled, as appropriate, to make country-specific estimates of the distribution of background blood lead levels among children and adults, along with information on specific sources of exposure where available. This study is registered with PROSPERO, number CRD42018108706. FINDINGS: Our search yielded 12 695 studies, of which 520 were eligible for inclusion (1100 sampled populations from 49 countries comprising 1 003 455 individuals). Pooled mean blood lead concentrations in children ranged from 1·66 µg/dL (SD 3·31) in Ethiopia to 9·30 µg/dL (11·73) in Palestine, and in adults from 0·39 µg/dL (1·25) in Sudan to 11·36 µg/dL (5·20) in Pakistan. Background values for blood lead level in children could be pooled in 34 countries and were used to estimate background distributions for 1·30 billion of them. 632 million children (95% CI 394 million-780 million; 48·5%) were estimated to have a blood lead level exceeding the US Centers for Disease Control's reference value of 5 µg/dL. Major sources of lead exposure were informal lead acid battery recycling and manufacture, metal mining and processing, electronic waste, and the use of lead as a food adulterant, primarily in spices. INTERPRETATION: Many children have a blood lead level exceeding 5 µg/dL in LMICs, despite leaded petrol phase-outs. Given the toxicity of lead, even at low amounts of exposure, urgent attention is required to control exposures and to expand population-based sampling in countries with no or scant data. FUNDING: This work was supported by the United States Agency for International Development (Cooperative Agreement number AID-OAA-A-16-00019).

[Estimation of Health Risk Posed by Road Traffic Noise in Japan Based on the Environmental Noise Guidelines for the European Region].

OBJECTIVES: Traffic noise exposure is associated with adverse health effects such as environmental sleep disorder, ischaemic heart disease (IHD), stroke and diabetes. The health risks posed by traffic noise were estimated to be quite high in European countries. However, in Japan, no estimation has ever been conducted. In the present study, we estimated the health risk posed by road traffic noise in Japan. METHODS: We estimated the risks of environmental sleep disorder (high sleep disturbance) and IHD caused by road traffic noise in Japan as of 2015 on the basis of existing noise-exposure estimates, vital statistics of deaths, and patient survey with exposure-response relationships proposed by the Environmental Noise Guidelines for the European Region issued in 2018. We employed old information on noise exposure in 1994 because it is the only information currently available in Japan. We also estimated the health risks of noise exposure levels that were equivalent to the Japanese environmental quality standards. RESULTS: The estimated numbers of patients with environmental sleep disorder and IHD caused by road traffic noise were approximately 1,200,000 and 9,000, respectively. The estimated number of mortalities from IHD was approximately 1,700. The noise exposure level equivalent to the Japanese noise standards caused a lifetime mortality rate of more than 10-2, which was extremely high as an environmental health risk. CONCLUSIONS: As in European countries, road traffic noise was one of the most important environmental risk factors in Japan. However, the current Japanese noise standards are insufficient for the protection of public health.

Deriving Compound-Specific Exposure Limits for Chemicals Used in Pharmaceutical Synthesis: Challenges in Expert Decision-Making Exemplified Through a Case Study-Based Workshop.

A workshop entitled "Deriving Compound-Specific Exposure Limits for Chemicals Used in Pharmaceutical Synthesis" was held at the 2018 Genetic Toxicology Association annual meeting. The objectives of the workshop were to provide an educational forum and use case studies and live multiple-choice polling to establish the degree of similarity/diversity in approach/opinion of the industry experts and other delegates present for some of the more challenging decision points that need to be considered when developing a compound-specific exposure limit (ie, acceptable intake or permissible or permitted daily exposure). Herein we summarize the relevant background and case study information for each decision point topic presented as well as highlight significant polling responses and discussion points. A common observation throughout was the requirement for expert judgment to be applied at each of the decision points presented which often results in different reasoning being applied by the risk assessor when deriving a compound-specific exposure limit. This supports the value of precompetitive cross-industry collaborations to develop compound-specific limits and harmonize the methodology applied, thus reducing the associated uncertainty inherent in the application of isolated expert judgment in this context. An overview of relevant precompetitive cross-industry collaborations working to achieve this goal is described.

Premature mortality due to air pollution in European cities: a health impact assessment.

BACKGROUND: Ambient air pollution is a major environmental cause of morbidity and mortality worldwide. Cities are generally hotspots for air pollution and disease. However, the exact extent of the health effects of air pollution at the city level is still largely unknown. We aimed to estimate the proportion of annual preventable deaths due to air pollution in almost 1000 cities in Europe. METHODS: We did a quantitative health impact assessment for the year 2015 to estimate the effect of air pollution exposure (PM2·5 and NO2) on natural-cause mortality for adult residents (aged ≥20 years) in 969 cities and 47 greater cities in Europe. We retrieved the cities and greater cities from the Urban Audit 2018 dataset and did the analysis at a 250 m grid cell level for 2015 data based on the global human settlement layer residential population. We estimated the annual premature mortality burden preventable if the WHO recommended values (ie, 10 µg/m3 for PM2·5 and 40 µg/m3 for NO2) were achieved and if air pollution concentrations were reduced to the lowest values measured in 2015 in European cities (ie, 3·7 µg/m3 for PM2·5 and 3·5 µg/m3 for NO2). We clustered and ranked the cities on the basis of population and age-standardised mortality burden associated with air pollution exposure. In addition, we did several uncertainty and sensitivity analyses to test the robustness of our estimates. FINDINGS: Compliance with WHO air pollution guidelines could prevent 51 213 (95% CI 34 036-68 682) deaths per year for PM2·5 exposure and 900 (0-2476) deaths per year for NO2 exposure. The reduction of air pollution to the lowest measured concentrations could prevent 124 729 (83 332-166 535) deaths per year for PM2·5 exposure and 79 435 (0-215 165) deaths per year for NO2 exposure. A great variability in the preventable mortality burden was observed by city, ranging from 0 to 202 deaths per 100 000 population for PM2·5 and from 0 to 73 deaths for NO2 per 100 000 population when the lowest measured concentrations were considered. The highest PM2·5 mortality burden was estimated for cities in the Po Valley (northern Italy), Poland, and Czech Republic. The highest NO2 mortality burden was estimated for large cities and capital cities in western and southern Europe. Sensitivity analyses showed that the results were particularly sensitive to the choice of the exposure response function, but less so to the choice of baseline mortality values and exposure assessment method. INTERPRETATION: A considerable proportion of premature deaths in European cities could be avoided annually by lowering air pollution concentrations, particularly below WHO guidelines. The mortality burden varied considerably between European cities, indicating where policy actions are more urgently needed to reduce air pollution and achieve sustainable, liveable, and healthy communities. Current guidelines should be revised and air pollution concentrations should be reduced further to achieve greater protection of health in cities. FUNDING: Spanish Ministry of Science and Innovation, Internal ISGlobal fund.

[A new occupational and environmental hazard - nanoplastic]. / Nowe zagrozenie zawodowe i srodowiskowe ­ nanoplastik.

Problems arising from the accumulation of plastic waste in the environment have become global. Appeals to stop the usage of disposable drinking straws or plastic cutlery did not come out without reason - 320 million tons of plastic products are produced annually, of which 40% are disposable items. More and more countries and private enterprises are giving up these types of items in favor of their biodegradable substitutes, e.g., cardboard drinking straws. Plastic waste in the environment is subject to a number of physicochemical interactions and biodegradation in which bacteria are involved. By using synthetic waste, they reduce the size of plastic garbage while increasing its dispersion in the environment. Small plastic particles, invisible to the naked eye, are called nanoplastic. Nanoplastic is not inert to living organisms. Due to its size, it is taken up with food by animals and passed on in the trophic chain. The ability to penetrate the body's barriers through nanoplastic leads to the induction of biological effects with various outcomes. Research studies on the interaction of nanoplastic with living organisms are carried out in many laboratories; however, their number is still a drop in the ocean of the data needed to draw clear-cut conclusions about the impact of nanoplastic on living organisms. There is also no data on the direct exposure to nanoplastic contamination at workplaces, schools and public utilities, standards describing the acceptable concentration of nanoplastic in food products and drinking water, and in vitro tests on nanoparticles other than polystyrene nanoparticles. Complementing the existing data will allow assessing the risks arising from the exposure of organisms to nanoplastic. Med Pr. 2020;71(6):743-56.

Variations in Athlete Heat-Loss Potential Between Hot-Dry and Warm-Humid Environments at Equivalent Wet-Bulb Globe Temperature Thresholds.

CONTEXT: Many organizations associated with sports medicine recommend using wet-bulb globe temperature (WBGT)-based activity-modification guidelines that are uniform across the country. However, no consideration has been given to whether the WBGT thresholds are appropriate for different weather conditions, such as warm-humid (WH) relative to hot-dry (HD), based on known differences in physiological responses to these environments. OBJECTIVE: To identify if personnel in regions with drier conditions and greater evaporative cooling potential should consider using WBGT-based activity-modification thresholds that differ from those in more humid weather. DESIGN: Observational study. SETTING: Weather stations across the contiguous United States. MAIN OUTCOME MEASURE(S): A 15-year hourly WBGT dataset from 217 weather stations across the contiguous United States was used to identify particular combinations of globe temperature, wet-bulb temperature, and air temperature that produce WBGTs of 27.9°C, 30.1°C, and 32.3°C. A total of 71 302 observations were clustered into HD and WH environmental conditions. From these clusters, maximum heat-loss potential and heat-flux values were modeled at equivalent WBGT thresholds with various activity levels, clothing, and equipment configurations. RESULTS: We identified strong geographic patterns, with HD conditions predominant in the western half and WH conditions predominant in the eastern half of the country. Heat loss was systematically greater in HD than in WH conditions, indicating an overall less stressful environment, even at equivalent WBGT values. At a WBGT of 32.3°C, this difference was 11 W·m-2 at an activity velocity of 0.3 m·s-1, which doubled for an activity velocity of 0.7 m·s-1. The HD and WH difference increased with the WBGT value, demonstrating that evaporative cooling differences between HD and WH conditions were even greater at a higher, rather than lower, WBGT. CONCLUSIONS: Potential heat loss was consistently greater in HD than in WH environments despite equal WBGTs. These findings support the need for further clinical studies to determine the appropriate WBGT thresholds based on environmental and physiological limits to maximize safety while avoiding unnecessary limitations.

Permitted Daily Exposure Values: Application Considerations in Toxicological Risk Assessments.

Permitted daily exposure (PDE) values are used by some toxicologists to support the safety qualification of various types of impurities found in a drug substance (DS) or drug product (DP). Permitted daily exposure values are important tools for the toxicologist, but one must be aware of their limitations to ensure that they are used appropriately and effectively in the risk assessment process. First, a toxicologist must always perform a comprehensive analysis of all available animal and human safety data for an impurity, including identifying any data gaps that may exist. Second, if adequate data are available and there are no genotoxicity concerns, an appropriate well-designed repeat-dose toxicity study in animals should be chosen to calculate the PDE. It is important to note that PDE values qualify general systemic toxicity and not necessarily local toleration end points such as irritation and sensitization that are more concentration than dose dependent. In addition, a PDE value calculated from a general toxicity study in animals may not necessarily qualify for reproductive toxicology end points. Lastly, PDE values should never be thought of as analytical limits for or acceptable levels of an impurity in a DS or DP, as this ignores quality considerations. Using safety information from several chemicals as proxy impurities, this article serves as an educational primer to facilitate a better understanding of the development and use of PDE values in the risk assessment process.

Reflections on the OECD guidelines for in vitro skin absorption studies.

At the 8th conference of Occupational and Environmental Exposure of the Skin to Chemicals (OEESC) (16-18 September 2019) in Dublin, Ireland, several researchers performing skin permeation assays convened to discuss in vitro skin permeability experiments. We, along with other colleagues, all of us hands-on skin permeation researchers, present here the results from our discussions on the available OECD guidelines. The discussions were especially focused on three OECD skin absorption documents, including a recent revision of one: i) OECD Guidance Document 28 (GD28) for the conduct of skin absorption studies (OECD, 2004), ii) Test Guideline 428 (TGD428) for measuring skin absorption of chemical in vitro (OECD, 2004), and iii) OECD Guidance Notes 156 (GN156) on dermal absorption issued in 2011 (OECD, 2011). GN156 (OECD, 2019) is currently under review but not finalized. A mutual concern was that these guidance documents do not comprehensively address methodological issues or the performance of the test, which might be partially due to the years needed to finalize and update OECD documents with new skin research evidence. Here, we summarize the numerous factors that can influence skin permeation and its measurement, and where guidance on several of these are omitted and often not discussed in published articles. We propose several improvements of these guidelines, which would contribute in harmonizing future in vitro skin permeation experiments.

Influence of the environment on cognitive-motor interaction during walking in people living with and without multiple sclerosis.

BACKGROUND: Motor and cognitive impairments are highly prevalent in people with multiple sclerosis (pwMS). The current theoretical frameworks of cognitive-motor interaction (CMI) suggest that the environment can influence both motor and cognitive performance during walking. However, the relationship between increasing environmental demands and CMI in pwMS remains to be elucidated. RESEARCH QUESTION: What is the impact of increased environmental demands on CMI during walking in people living with and without MS? METHODS: Twenty pwMS and 20 age-matched healthy adults (HA) participated in this cross-sectional study. Participants (age = 57.6 ± 7.8 years) performed four walks (baseline walking (BW), obstacle walking (OW), narrow walking (NW), and narrow with obstacles (NO)) in single-task and dual-task (serial-7 subtraction test) conditions. The dual-task costs (DTC) of gait (% change in walking time) and cognition (% change in correctly verbalized utterances) were calculated to quantify CMI. Secondary outcomes included physiological profile assessment (PPA), measures of cognition and falls efficacy scale international (FES-I). RESULTS: Mixed-factor ANOVAs revealed no main effect of task (F = 1.71, p = 0.196) and group (F = 0.71, p = 0.406) on DTC of gait, while there were significant main effects of both task (F = 23.75, p < 0.001) and group (F = 6.53, p = 0.015) on DTC of cognition. Simple main effects revealed that pwMS had a significantly higher DTC of cognition during BW (+37.6 %, p=0.013), NW (+34.2 %, p=0.014) and NO (+49 %, p=0.016) compared to HA. Additionally, DTC of cognition increased during the more environmentally demanding conditions compared to BW (range: +28.4 % to +54.2 %, all p-values<0.01) in both pwMS and HA. Only DTCs of cognition were significantly correlated with PPA and FES-I. SIGNIFICANCE: The study findings suggest that CMI may be influenced by the individual/environment at levels above those described by the more mechanistic theories of attention.

What are the effects of PFAS exposure at environmentally relevant concentrations?

The group of synthetic chemicals known as poly and per-fluoroalkyl substances (PFAS) are currently of high concern to environmental regulators and the public due to their widespread occurrence, resistance to degradation and reported toxicity. However, little data exists on the effects of exposure to PFAS at environmentally relevant concentrations and this hampers the effective management of these compounds. This paper reviews current research on the occurrence and ecotoxicology of PFAS at environmentally relevant doses to assess their potential biological impacts. Hazard Quotient (HQ) analysis was undertaken as part of this assessment. Most PFAS detected in the environment were found to have a HQ risk value of <1 meaning their reported concentrations are below their predicted no effect concentration. This indicates many reported toxic effects of PFAS are, theoretically, unlikely to occur outside the laboratory. However, lack of information on new PFAS as well as their precursors and degradation products, coupled with lack of knowledge of their mixture toxicity means our understanding of the risks of PFAS is incomplete, especially in regard to sub-lethal and/or chronic effects. It is proposed that the development of molecular markers for PFAS exposure are needed to aid in the development of environmental PFAS regulations that are effective in fully protecting the environment.

Environmental magnetic field in a Neonatal Intensive Care Unit. A relevant verification. / Campo magnético ambiental en una Unidad de Terapia Intensiva Neonatal. Importancia de su verificación.

Preterm infants are born with immature organs, thus affecting the immune system. Electromagnetic fields influence melatonin production with low exposure levels. These infants require medical equipment 24/7 to recover, so they are constantly exposed to magnetic fields during their stay in the Intensive Care Unit. Our objective was to measure magnetic field levels generated around each incubator using a gauss meter and compare our results to the 2010 recommendations by the International Commission on Non-Ionizing Radiation Protection and the IEC 60601-1-2:2004 standard by the International Electrotechnical Commission (IEC). Among 11 hospitalized newborn infants, radiation was found within the recommended limits, but there was electromagnetic interference resulting from medical equipment layout problems in the unit.

Los neonatos pretérminos nacen con inmadurez en los órganos, lo que lleva al compromiso del sistema inmunológico. Los campos electromagnéticos afectan la producción de melatonina a niveles bajos de exposición. Estos niños necesitan equipamiento médico las 24 horas del día para su recuperación, por lo que están expuestos a los campos magnéticos durante todo el tiempo que se encuentren en la Unidad de Terapia Intensiva. El objetivo fue medir los niveles de campo magnético que se generan alrededor de cada una de las incubadoras utilizando un gaussímetro y comparar los resultados con las recomendaciones de la Comisión Internacional para la Protección contra las Radiaciones No Ionizantes de 2010 y la norma de la International Electrotechnical Commission (IEC) IEC 60601-1-2:2004. En 11 neonatos internados, los valores de radiación se encontraban dentro de los recomendados, pero existía interferencia electromagnética por problemas de disposición de los equipos en el área.

Too loud? Do powered hand dryers violate federal noise exposure standards?

OBJECTIVE: The aim of this study was to determine if high-powered air hand dryers produce sufficient noise to warrant concern over acoustic trauma as determined by federally established standards. STUDY DESIGN: Prospective observational field data collection SETTING: Urban and suburban community SUBJECTS AND METHODS: Using a NIOSH developed and calibrated soundmeter app, powered hand dryers were measured throughout two metropolitan areas. Ear level measurements were performed while drying wet hands. Recorded variables included average LAeq, Time-Weighted Average, Max and Peak Levels, Noise Dose, and Projected Dose according to NIOSH and OSHA standards, and all three major weighting networks (A, C, and Z). RESULTS: Fifty-four trials were performed at 27 locations. Average dryer run time was 28.9 s (range 14-45 s). Average LAeq (dBA), average maximum level (dBA), and average TWA (dBA) were 90.46 ± 5.32, 94.86 ± 5.73, 59.90 ± 6.80, respectively. The noise generated exceeded published manufacturer specifications. However, even with estimated cumulative daily exposure, the noise generated by these dryers did not exceed federal safety standards. CONCLUSIONS: Air-powered hand dryers produce noise output at a level that many would find subjectively uncomfortable with some brands/models consistently producing noise in excess of 90 dBA. Nonetheless, these dryers do not produce sound exceeding NIOSH standards for noise exposure.

Treating the Disease, Not the Symptom: Beyond NSAIDs.

Mitigating inflammation is clearly important in cancer prevention and control. Traditionally, pharmaceuticals have taken the lead in this problem. In an attempt to 'head them off at the pass', this Forum takes a hard look at the concept of 'better living through chemicals' and limiting proinflammatory chemicals entering the body.

Carbon monoxide poisoning.

Despite established exposure limits and safety standards as well as the availability of carbon monoxide (CO) alarms, each year 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO or from longer exposures to lower levels. Common symptoms can include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status. Some patients may have chest pain, shortness of breath, and myocardial ischemia, and may require mechanical ventilation and treatment of shock. Individuals poisoned by CO often develop brain injury manifested by neurological problems, including cognitive sequelae, anxiety and depression, persistent headaches, dizziness, sleep problems, motor weakness, vestibular and balance problems, gaze abnormalities, peripheral neuropathies, hearing loss, tinnitus, Parkinsonian-like syndrome, and other problems. In addition, some will have cardiac issues or other ailments. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO2) hastens COHb elimination and favorably modulates inflammatory processes instigated by CO poisoning, an effect not observed with breathing normobaric oxygen. Hyperbaric oxygen improves mitochondrial function, inhibits lipid peroxidation transiently, impairs leukocyte adhesion to injured microvasculature, and reduces brain inflammation caused by the CO-induced adduct formation of myelin basic protein. Based upon three supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO2 should be considered for all cases of acute symptomatic CO poisoning. Hyperbaric oxygen is indicated for CO poisoning complicated by cyanide poisoning, often concomitantly with smoke inhalation.