Histomorphological and Histochemical Alterations Following Short-term Inhalation Exposure to Sulfur Mustard on Visceral Organs of Mice

Toxic effects of inhaled sulfur mustard (SM) on the histology of visceral organs was investigaed by exposing mice to 84. 6mg/m3 for 1h duration, using controlled single exposure conditions. A progressive fall in body weight from third day onwards was noticed. Light microscopic examination of the pulmonary tissue of these animals at 6 h post exposure revealed that the tracheobronchial epithelium remained intact, but was infiltrated by inflammatory cells. By 24 h post exposure, the mucosecretory cells were destroyed. The indanunatory reaction was maximum at 48 h. By 7th day post exposure there was swelling and vacuolation of lung parenchymal cells and thrombi formation. In addition SM caused congestion and hemorrhage at alveolar level. SM also caused granulovacuolar degeneration with perinuclear clumping of the cytopasm of hepatocytes and renal parenchymal cells. Renallesions were chazacterized by congestion and hemorrhage. Among visceral tissues, maximum atrophywas observed in spleen. Distribution of lesions increased with post exposure period. The maximum lesions were observed at 7th day post-exposure.

A Genetic Susceptibility Study of Lung Cancer Risk Potentially Associated with Polycyclic Aromatic Hydrocarbon Inhalation Exposure

For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of inhalation exposure for decades. Polycyclic aromatic hydrocarbons （PAHs） are the by-products of incomplete combustion.

The risk factors and threshold level of subchronic inhalation exposure of reclaimed water

Inhalation of reclaimed water is known to cause lung infammation,and free endotoxins have been shown to be a major risk factor for acute exposure.Subchronic exposure has also been shown to induce infammatory responses with visible tissue damage.However,subchronic risk factors have yet to be identified,and a threshold for the protection of occupational populations during urban reuse is necessary.In this study,potential risk factors in reclaimed water were examined by subchronic exposure with fractionated reclaimed water,and the health risk threshold was tested with a series of diluted reclaimed water.Accordingly,following a 12-week exposure,macromolecules and microorganisms were found to be two major risk factors in reclaimed water that could cause pulmonary infammation,including increased proportion of polymorphonuclear leukocytes in bronchoalveolar fuid,formation of inducible bronchus-associated lymphoid tissue,and elevation of Immunoglobulin A levels.Moreover,infammation persisted after a 4-week recovery period.The calculated threshold of reclaimed water exposure for mice was 31.8 Endotoxin Unit(EU)/(kg·day)under when exposed to 50%additional relative humidity from reclaimed water at 25℃ for 2 hr/day.Meanwhile,the subchronic threshold estimate for humans under the same exposure conditions was found to be 12.2 EU/(kg·day),corresponding to endotoxin levels of 61.7 EU/mL in reclaimed water.The threshold level of endotoxin was lower than that in most non-potable reclaimed water.The findings of this study suggest that occupational exposure of reclaimed water can serve as a potential risk to workers.

Impact of indoor ventilation efficiency on acetone inhalation exposure concentration and tissue dose in respiratory tract

A significant feature of the indoor environment is the heterogeneity of airflow and pollutant distributions,which are primarily dependent on ventilation systems.In the case of short-and high-concentration exposures to hazardous chemical pollutants,it may be necessary to precisely determine the concentration in the breathing zone or,more directly,the inhalation exposure concentration in the respiratory tract,rather than the representative room average concentration in an indoor environment,because of the non-uniformity of pollutant concentration distributions.In this study,we developed a computer-simulated person with a detailed respiratory system to predict inhalation exposure concentration and inhalation dose via transient breathing and reported a demonstrative numerical simulation for analyzing acetone concentration distributions in a simplified model room.Our numerical analysis revealed that the ventilation efficiency distribution in a room could change significantly by changing the design of the ventilation system,and that the inhalation exposure concentration estimated by a computer-simulated person could differ from the representative concentration,such as perfect-mixing or volume-averaged acetone concentration,by a factor of two or more.

Assessment of potential dermal and inhalation exposure of workers to the insecticide imidacloprid using whole-body dosimetry in China

In China, although improvements to the pesticide registration process have been made in la thirty years, no occupational exposure data are required to obtain a commercial license for pesticide product. Consequently, notably little research has been conducted to establish a exposure assessment procedure in China. The present study monitored the potential derm operator exposure from knapsack electric sprayer wheat field application of imidacloprid Liaocheng City, Shandong Province and in Xinxiang City, Henan Province, China, usin whole-body dosimetry. The potential inhalation exposure was determined using a person air pump and XAD-2 sample tubes. The analytical method was developed and validate including such performance parameters as limits of detection and quantification, linear rang recovery and precision. The total potential dermal and inhalation exposures were 14.20, 16.815.39 and 20.78 mL/hr, respectively, for the four operators in Liaocheng and Xinxian corresponding to 0.02% to 0.03% of the applied volume of spray solution. In all trials, the low part（thigh, lower leg） of the body was the most contaminated, accounting for approximate76% to 88% of the total exposure. The inhalation exposure was less than 1% of the tot exposure. Such factors as the application pattern, crop type, spray equipment, operat experience and climatic conditions have been used to explain the exposure distribution ov the different parts of the body. As indicated by the calculated Margin of Exposure, the typic wheat treatment scenarios when a backpack sprayer was used are considered to be safe terms of imidacloprid exposure.

Pulmonary Toxicity of a Formulated Preparation of Fenvalerate in Rats Subchronically Exposed by Nose Only Inhalation for 90 Days

Objective The pulmonary toxicity of a commercially available formulated preparation of Fenvalerate (Fen), a synthetic pyrethroid has been studied in rats following subchronic nose only inhalation exposure route. Method Adult male rats were exposed to Fen for 4h/day, 5 days a week for 90 days by using Flow Past Dynamic Nose only Inhalation Chamber. Results Fen exposed rats showed a significant increase in enzymatic activities of lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and γ-glutamyl transferase (γ-GT) which are considered as biochemical indicators of pulmonary damage. The concomitant histopathological examination of Fen exposed rats' lung revealed inflammatory changes viz., influx of mononuclear cells admixed with a few giant cells in alveolar lumen, hypetrophied bronchiolar and alveolar epithelial lining cells and presence of edematous fluid in alveolar lumen alongwith congested parenchymatous blood vessels. Conclusion These results for the first time indicate the pulmonary toxic effects of a commonly used formulated Fen preparation by using rat model and nose only inhalation as the route of exposure.

Acute Inhalation Toxicity Study of 2-Fluoroaceta mide in Rats

One of the most potent rodenticides is 2_fluoroacetamide (2_FA). Toxicity of this chemical is well documented. However, its inhalation toxicity data is not available in the literature. Hence, \{acute\} inhalation toxicity study was carried out by exposing male and female rats to aerosols of 2_FA at different concentrations for 4 h in a dynamically operated whole body inhalation exposure chamber. During and after the inhalation exposure the rats were less active, and showed mild tremors and convulsions. At higher concentrations the rats died after 2_3 days. The estimated 4_h LC 50 for male and female rats was 136.6 and 144.5 mg·m -3 respectively. Exposure to 0.7 LC 50 for 4 h duration showed an increase in the liver weight of male and female rats 7 days after exposure. Various haematological and biochemical variables determined were within the normal limits. However, histological findings showed injured lung as indicated by desquamation and necrosis of the epithelium of the respiratory tract. Marked hypertrophy of hepatocytes displaying strong acidophilic granulated cytoplasm was observed. Focal dilatation of renal proximal tubules in kidney with cytoplasmic vacuolation, and irregularly placed pyknotic nuclei were seen. The present study shows that 2_FA is a highly toxic chemical through the inhalation route based on the LC 50 value. Consequently necessary precautions should be taken during its handling.

Diurnal variation of nitrated polycyclic aromatic hydrocarbons in PM_(10) at a roadside site in Xiamen,China

Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At the same time, six PMt0 samples were collected from a nearby roadway tunnel for comparison. Six NPAHs, namely 9-nitroanthracene, 2- and 3-nitrofluoranthene, 1- nitropyrene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene, were identified and quantified using GC/MS in negative ion chemical ionization mode. The average total concentration of six NPAHs （~NPAHs） in the cold season （26 Nov-31 Dec） was 2.3 （daytime） and 9.9 （nighttime） times higher than those in the warm season. Significant statistical difference （p 〈 0.01, 2-tailed） of ∑NPAHs between daytime and nighttime was found during both the warm and cold seasons. NPAHs were significantly positively correlated with their parent PAHs and nitrogen dioxide but negatively correlated with ambient temperature. The ratio of 2 ＋ 3-nitrofluoranthene to 1- nitropyrene exhibited a similar diurnal pattern as ZNPAHs and was generally greater than 5, indicating the importance of secondary atmospheric formation. The diurnal variations of NPAHs were all influenced by the diurnal variations of PAHs, nitrogen dioxide, sunlight, and temperature. The daily inhalable exposure to the six NPAHs in the tunnel was much higher than the roadside values in the warm season but only slightly higher than those in the cold season.

Arsenic species in electronic cigarettes:Determination and potential health risk

Human exposure to contaminants from electronic cigarettes(e-cigarettes)and the associated health effects are poorly understood.There has been no report on the speciation of arsenic in e-liquid(solution used for e-cigarettes)and aerosols.We report here determination of arsenic species in e-liquids and aerosols generated from vaping the e-liquid.Seventeen e-liquid samples of major brands,purchased from local and online stores in Canada and China,were analyzed for arsenic species using high-performance liquid chromatography and inductively coupled plasma mass spectrometry.Aerosols condensed from vaping the eliquids were also analyzed and compared for arsenic species.Six arsenic species were detected,including inorganic arsenate(iAsⅤ),arsenite(iAsⅢ),monomethylarsonic acid(MMA),and three new arsenic species not reported previously.In e-liquids,iAsⅢwas detected in 59%,iAsⅤin 94%,and MMA in 47%of the samples.In the condensate of aerosols from vaping the e-liquids,iAsⅢwas detected in 100%,iAsv in 88%,and MMA in 13%of the samples.Inorganic arsenic species were predominant in e-liquids and aerosols of e-cigarettes.The concentration of iAsⅢin the condensate of aerosols(median 3.27μg/kg)was significantly higher than that in the e-liquid(median 1.08μg/kg)samples.The concentration of inorganic arsenic in the vaping air was approximately 3.4μg/m3,which approaches to the permissible exposure limit(10μg/m3)set by the United States Occupational Safety and Health Administration(OSHA).According to the Environmental Protection Agency’s unit risk factor(4.3×10-3 perμg/m3)for inhalation exposure to inorganic arsenic in the air,the estimated excess lung cancer risk from lifetime exposure to inorganic arsenic in the ecigarette vaping air(3.4μg/m3),assuming e-cigarette vaping at 1%of the time,is as high as1.5×10-4.These results raise health concerns over the exposure to arsenic from electronic cigarettes.

Decreasing inhaled contaminant dose of a factory worker through a hybrid Emergency Ventilation System:Performance evaluation in worst-case scenario

Air pollution is detrimental to human health,causing several human illnesses.The industrial microenvironment generates high levels of indoor airborne pollutants,becoming a pervasive issue for workers.It is essential to im-prove the indoor air quality in this workplace by applying enhanced ventilation systems to minimize inhalation risk.Displacement ventilation is used in industrial buildings because of its stratified air distribution and low cost.However,in case of accidental pollutant release,an enhancement is needed to minimize inhalation exposure.This study proposes a hybrid emergency ventilation system using localized push-pull ventilation to improve the installed displacement ventilation system of a representative workshop.Computational fluid dynamics was ap-plied to calculate steady-state indoor air flow and volume-averaged pollutant concentration.System performance was evaluated in terms of source position;a computer simulated person was integrated to the building to confirm effectiveness against personal inhalation.Results showed marked improvement in performance when push-pull technique was used:room-averaged concentration diminished up to 91%while ventilation rate only increased 4%.Inhaled pollutant mitigation was achieved but performance dependence against leakage source and personal position was confirmed.