Wide Range Of Toxic Chemicals Research Articles

E-Waste: a Concise Update on Global Movement, Impacts, Management, and Site Remediation

The rapid rise of electronic waste (e-waste) worldwide has become a public health concern. Wealthy countries are disposing of their e-waste to other countries taking advantage of their less stringent environmental laws and regulations. China used to receive large amounts of e-waste through Hong Kong (a free port) but banned the entry of e-waste in 2013. Salvaging or recycling different parts of the e-waste using primitive and uncontrolled techniques generated a wide range of toxic chemicals (mainly heavy metals and persistent organic pollutants). Most studies concerning the environmental and health impacts of the emitted toxic chemicals were conducted in China. The principal aim of this short article is to review the various environmental problems and health impacts of e-waste recycling, policies, management, and remediation of contaminated sites. Out of the primitive methods used for recycling, the two most destructive ones causing harm to the environment and human health are (1) Open-burning of e-waste for disposing of the salvaged e-waste and (2) Acid-stripping of electronic boards for collecting precious metals (gold, silver, platinum). There is sufficient evidence showing the associations between the toxic chemicals in different media (i.e., water, soil/sediment, air) and local food items (i.e., fish, meat, vegetables), linking with body burdens (hair, milk, placenta) of workers and residents. The epidemiological data further demonstrated the abrupt rise of several significant diseases (i.e., respiratory disease, cardiovascular disease, malignant tumors) in Taizhou (China), one of the two e-waste recycling sites. Effective policies and vigorous enforcement in managing e-waste are essential. International cooperation is necessary to prohibit the transboundary movement of e-waste. Sites contaminated by e-waste recycling contain incredibly high concentrations of toxic pollutants, which should be removed using excavation, degradation (via microbes, nanoparticles, biochar), soil washing, etc. Planting appropriate plants with associated rhizospheric microbes would achieve longer-term stability.

Recycled Smelter Slags for In Situ and Ex Situ Water and Wastewater Treatment—Current Knowledge and Opportunities

Slags from the ferrous and nonferrous metallurgical industries have been used to treat toxic contaminants in water and wastewater. Using slag as a recycling or renewable resource rather than a waste product has environmental and economic benefits. Recycled smelter slags can be used in both in situ and ex situ treatment. However, their application has some limitations. One of the challenges is how to handle spent slag adsorbents, as they contain the accumulation of solid waste loaded with high concentrations of toxic contaminants. These challenges can be overcome by regeneration, recycling, reuse, and immobilization treatment of spent slag adsorbents. The present paper explored the scientific and technical information about the composition, reaction mechanisms, adsorption capacity, and opportunities of recycled slags while adsorbing toxic compounds from contaminated water. It comprehensively reviewed the current state of the art for using smelting slags as sustainable adsorbents for water and wastewater. The study revealed that ferrous slags are more effective in removing a wide range of toxic chemicals than nonferrous smelter slags. It investigated the necessary improved approach through the 5Rs (i.e., reduce, reuse, recycle, remove, and recover) using smelter slags as reactive materials in ex situ and in situ treatment.

Toxic chemicals from uncontrolled e-waste recycling: Exposure, body burden, health impact

Uncontrolled electronic-waste (e-waste) recycling processes have induced serious environmental pollution and human health impacts. This paper reviewed studies on the wide range of toxic chemicals through the use of primitive recycling techniques, their transfer to various ecological compartments, and subsequent health impacts. Results indicated that local food items were heavily polluted by the pollutants emitted, notably heavy metals in vegetables, rice, fish and seafood, and persistent organic pollutants (POPs) in livestock. Dietary exposure is the most important exposure pathway. The associations between exposure to e-waste and high body burdens of these pollutants were evident. It seems apparent that toxic chemicals emitted from e-waste activities are causing a number of major illnesses related to cardiovascular, digestive and respiratory systems, according to the information provided by a local hospital (Taizhou, an e-waste recycling hot spot in China). More epidemiological data should be made available to the general public. It is envisaged that there are potential dangers of toxic chemicals passing on to the next generation via placental transfer and lactation. There is a need to monitor the development and health impacts of infants and children, born and brought up in the e-waste sites.

Modified sorbents based on walnut shell for sorption of toxic gases

In this article, low-cost carbon-based nanoporous materials were synthesized and impregnated in order to offer a sufficient protection for a wide range of toxic chemicals. The microstructure analysis of the samples reveals that the activation promotes the formation of a higher number of small pores and the development of a spongy texture of the sorbents leading thus to an increase in carbon content. The activated samples have apparent micro-mesoporosity confirmed by the corresponding isotherms of low-temperature adsorption of nitrogen. Furthermore, it has been shown that the activation procedure leads to samples with different acidity and this surface property has a marked influence on the performance of the materials. The results of a breakthrough time study for vapors of inorganic and organic substances indicate that the impregnations with Cu and Co are the most suitable for obtaining a universal sorbent. In this regard, an activated carbon impregnated with cobalt that can outperform commercial reference materials intended for this specific application has been developed in this work.

Water-Soluble Chemical Vapor Detection Enabled by Doctor-Blade-Coated Macroporous Photonic Crystals

Water-soluble chemicals, involving a wide range of toxic chemicals in aqueous solutions, remain essential in both daily living or industrial uses. However, most toxicants are evaporated with water through their use and thus cause deleterious effects on the domestic environment and health in humans. Unfortunately, most current low-dose chemical vapor detection technologies are restricted by the use of sophisticated instruments and unable to promptly detect the quantity of diverse toxicants in a single analysis. To address these issues, this study reports the development of simple and fast chemical vapor detection using doctor-blade-coated macroporous poly(2-hydroxyethyl methacrylate)/poly(ethoxylated trimethylolpropane triacrylate) photonic crystals, in which the poly(2-hydroxyethyl methacrylate) has strong affinity to insecticide vapor owing to a favorable Gibbs free energy change for their mixing. The condensation of water-soluble chemical vapor therefore results in a significant reflection peak shift and an obvious color change. The visual colorimetric readout can be further improved by increasing the lattice spacing of the macroporous photonic crystals. Furthermore, the dependence of the reflection peak position on vapor pressure under actual conditions and the reproducibility of vapor detecting are also evaluated in this study.

Advancing Metal‐Organic Frameworks toward Smart Sensing: Enhanced Fluorescence by a Photonic Metal‐Organic Framework for Organic Vapor Sensing

AbstractPolymer‐based colloidal crystals are promising materials for the enhancement of fluorescent emissions, however, due to limited porosity, they are not yet readily deployed in chemical vapor sensing. On the contrary, metal‐organic frameworks (MOFs) are highly porous with an exceptional ability to detect a wide range of toxic chemicals through fluorescence. Here, it is shown for the first time how enhanced fluorescence of a fluorophore can be achieved by incorporating a fluorescent dye into a template‐free periodically structured MOF film. A 200‐fold fluorescent intensity amplification is observed when Nile red (NR) dye is adsorbed on zeolitic imidazolate framework‐8 (ZIF‐8) particles and is then assembled into a colloidal crystal film (NR∼ccZIF‐8) when compared to the disordered film (NR∼ZIF‐8). The NR∼ccZIF‐8 film shows a response to 100 ppm of acetone vapor at room temperature with a detection limit of 60 ppm. The NR∼ccZIF‐8 film shows more than 40 times higher sensitivity to toluene vapor at 770 ppm than NR adsorbed on polystyrene particles forming a colloidal crystal film. From this study, it is expected that MOFs will play a role in the future development of smart sensors for chemical and biomedical applications.

Biomonitoring in firefighters for volatile organic compounds, semivolatile organic compounds, persistent organic pollutants, and metals: A systematic review

Firefighters are exposed to a wide range of toxic chemicals due to combustion, with numerous biomonitoring studies completed that have assessed exposure. Many of these studies focus on individual classes of chemicals, with a few considering a broad range of systemic exposures. As yet, no review process has been undertaken to comprehensively examine these studies. The aims of this review are to: (1) ascertain whether biomonitoring studies pertaining to firefighters demonstrate occupational exposure to volatile organic compounds, semivolatile organic compounds, and metals; (2) determine and present results of biomonitoring studies; (3) provide any recommendations presented from the literature that may support exposure mitigation; and (4) suggest future study parameters that may assist in providing a greater understanding surrounding the occupational exposure of firefighters. A systematic review was undertaken with regards to firefighters and biomonitoring studies utilising the matrices of blood, urine, semen and breast milk. This yielded 5690 results. Following duplicate removal, inclusion and exclusion criteria screening and full text screening, 34 studies remained for review. Results of over 80% of studies analysed determined firefighters to experience occupational exposure. Results also show firefighters to be exposed to a wide range of toxic chemicals due to fire smoke; potentially exceeding the range of exposure of other occupations. As firefighters may face increased risk of health effects due to the additive, synergistic, and/or antagonistic effects of chemical exposure, all care must be taken to reduce exposure. This may be achieved by considering tactical decisions, increased personal hygiene, and thorough decontamination procedures. Future biomonitoring studies recognising and assessing the range of chemical exposure firefighters face would be beneficial.

110th Anniversary: Molecular Structure Effects on Mass Transfer of C10 Hydrocarbons in BPL Activated Carbon

Adsorbent filters often use activated carbons to remove a wide range of toxic chemicals from air. It is of interest to know if filter performance for these compounds can be diffusion limited as a r...

Chemical pollution and seafood safety, with a focus on mercury: The case of Pearl River Delta, South China

Abstract Most of the fish consumed in Hong Kong are farmed fish, including freshwater and marine fish, which are highly susceptible to various chemicals discharged from industrial sites nearby. It is recognized that emissions from coal-power plants are major sources of Hg in the environment worldwide. The situation is serious in the Pearl River Delta, South China, with a high demand of electricity, to support rapid development of various industries. In addition, the area has become the world’s manufacturer for electrical/electric equipment, textiles, footwear, furniture, etc., emitting a wide range of toxic chemicals into the environment. In fact, “chemical food contaminants” is one of the 3 key global food safety concerns. Food safety is any action and policy which ensure food is safe, in the entire food chain, i.e. from production to consumption (WHO, 2013). This article attempts to review environmental health issues related to persistent toxic substances (PTS), with a focus on Hg; from biogeochemistry ecology epidemiology to policy and management, citing examples related to South China.

A Leaf-Inhabiting Endophytic Bacterium, Rhodococcus sp. KB6, Enhances Sweet Potato Resistance to Black Rot Disease Caused by Ceratocystis fimbriata.

Rhodococcus species have become increasingly important owing to their ability to degrade a wide range of toxic chemicals and produce bioactive compounds. Here, we report isolation of the Rhodococcus sp. KB6, which is a new leaf-inhabiting endophytic bacterium that suppresses black rot disease in sweet potato leaves. We determined the 7.0 Mb draft genome sequence of KB6 and have predicted 19 biosynthetic gene clusters for secondary metabolites, including heterobactins, which are a new class of siderophores. Notably, we showed the first internal colonization of host plants with Rhodococcus sp. KB6 and discuss its potential as a biocontrol agent for sustainable agriculture.

Reducing Hazardous Chemical Exposures in the Neonatal Intensive Care Unit

A wide range of toxic chemicals have been found in the umbilical cord blood of newborns, indicating the potential for health risks from chemical exposure that begin in utero. The neonatal intensive care unit (NICU) setting may also have potential chemical exposures that create health risks. Given the extreme vulnerability of this patient population, it is critical to minimize unnecessary hazardous chemicals. Neonatal intensive care unit nurses have an important role to play in making the NICU as safe as possible for their patients and themselves. This article will focus on the human health effects of several chemical exposures commonly found in the NICU for which nurses can help to eliminate or select safer alternatives: (1) diethylhexyl phthalates (a plasticizer commonly found in intravenous tubing/bags and other products); (2) bisphenol A (commonly found in the lining of baby formula cans); (3) personal care products used in the NICU; (4) cleaning, sterilants, and disinfectants; and (5) mercury. A tool for assessing environmental health risks will be presented and associated intervention options including purchasing policies; hospital-wide chemical policies; and development of institutional infrastructures, such as Green Teams, to address NICU and hospital-wide environmental health concerns. Nursing's evolving role in environmental health will be reviewed.

Development and evaluation of reverse polyethylene samplers for marine phase ii whole‐sediment toxicity identification evaluations

Marine and estuarine sediments accumulate contaminants and act as a sink for a wide range of toxic chemicals. As a result, the sediments themselves can become a source of contamination. At sufficient levels, contaminated sediments can cause benthic impairments and toxicity to marine organisms. Among the wide range of contaminants, nonionic organic contaminants (NOCs) are a primary cause of toxicity in marine sediments. Toxicity identification evaluations (TIEs) are used to characterize and identify chemicals causing toxicity in effluents, interstitial waters, and whole sediments using whole-organism endpoints. Phase I whole-sediment TIE methods for NOCs exist, but the development of phase II TIE methods for NOCs is a current research challenge. In the present study, the use of reverse polyethylene samplers (RePES) for phase II methods is examined. Various RePES designs were evaluated in an experimental design study with NOC chemical solutions. Based on equilibration time and proximity of measured NOC water concentrations in the reconstituted system to theoretical concentrations, a nontriolein design with loading of chemical solutions on the inside of the polyethylene tubing was chosen as most effective. A partitioning study demonstrated NOCs partitioned between the RePES and water as well as between the water and air, as expected using this nontriolein RePES design. Finally, a sediment toxicity study comparing the nontriolein RePES to contaminant-spiked sediments was conducted. The nontriolein RePES design was capable of successfully recreating the toxicity and water concentrations observed with the intact sediments.

Diverse Toxic Chemicals Disrupt Cell Function through a Common Path

Diverse Toxic Chemicals Disrupt Cell Function through a Common Path

Dynamics of the trimeric AcrB transporter protein inferred from a B‐factor analysis of the crystal structure

The Escherichia coli AcrB multidrug transporter recognizes a wide range of toxic chemicals and actively extrudes them from cells. The molecular basis of multidrug transport in AcrB remains unknown. Herein, we describe normal mode analyses to study important regions for drug recognition and extrusion in this transporter. Based on the X-ray structure of AcrB, an elastic network model has been able to correct errors arising from crystal imperfection in the experimental B-factors. The results allow us to understand the functional dynamics of this membrane protein. It is expected that this technique can be applied to other membrane proteins with known structures.

Evaluation of the factors relating combined sewer overflows with sediment contamination of the lower Passaic River

The relationship between combined sewer overflows (CSOs) and sediment contamination of the lower Passaic River in New Jersey was evaluated to identify the nature of toxic chemical inputs to the river, estimate the magnitude of CSO inputs to other sources and assess the potential overall impact on sediment quality. Of the estimated 5000 facilities that discharge industrial effluent to the combined sewerage system along the Passaic River, approximately 400 facilities hold National Pollutant Discharge Elimination System (NPDES) permits. Seventy-eight permitted facilities, representing 14 major industrial classes with discharges exceeding 190 000 1 day −1, were identified within 33 CSO districts that are below the Second River and serviced by the Passaic Valley Sewerage Commission. A wide range of toxic chemicals, including heavy metals, pesticides, polychlorinated dibenzo- p-dioxins and dibenzofurans, polychlorinated biphenyls and polycyclic aromatic hydrocarbons were found to be associated with numerous industries located within the CSO districts. Many of these chemicals have been measured in CSO discharges to the river during wet weather flow events and have also been measured in river sediments. The magnitude of the CSO discharges (billions of litres per year) to the lower Passaic River, combined with the nature of the chemicals used and discharged to the system by industrial sources, indicates that CSOs represent an historic and ongoing source of toxic pollutants to the river. While the US Environmental Protection Agency (EPA) has recently developed an aggressive programme for reducing the impact of CSOs on the nation's waters, it will likely be many years before the benefits of this programme are realized, particularly in areas with antiquated sewer systems such as those within the Passaic River basin.

Urinary mutagens in cosmetologists and dental personnel

Cosmetologists are occupationally exposed to a wide range of toxic chemicals both dermally and by inhalation. Since many of these chemicals are mutagens and may be excreted in urine, the Ames Salmonella typhimurium assay was used to determine the presence of direct-acting and promutagens in the urine of practicing cosmetologists in central New York State. A comparable group (age, gender, smokers) of dental hygienists and assistants in the same geographic area was used as the control cohort. The cosmetologists had a significantly higher (39 vs. 24%, p less than .03) frequency of direct-acting urinary mutagens but there was no difference between the groups in the frequency of promutagens. In the multivariate model, cosmetologists were at two times the risk of direct-acting mutagens compared to dental workers. Smoking regularly, within 24 h of taking the urine sample, and the number of cigarettes smoked daily were not associated significantly with direct-acting mutagens in urine. Similarly, having had a hair permanent or hair dyed within 7 d of urine sampling, years of employment, age, gender and use of protective gear were not predictive of direct-acting urinary mutagens. In contrast, employment was not associated with urinary promutagens but the risk was significantly increased with increasing age and cigarette smoking. Among possible adverse health symptoms queried, only the prevalence of skin rashes differed between the cosmetologists (29%) and dental personnel (15%) (p less than .05).