摘要:

The effects of simultaneous exposure to ozone (O3) and sulfuric acid [H2SO4, 0.23 μm volume median diameter (VMD)] and a single exposure to ultrafine (<0.1 μm VMD) H2SO4under various conditions were studied using the infectivity/mortality and the ciliary beating frequency model systems. A 3‐h exposure to a combined aerosol of 196 μg O3/m3and 483 or 241 μg A2SO4/m3significantly increased the susceptibility of mice to a laboratory‐induced respiratory infection. However, exposure to 543 μg ultrafine H2SO4/m3for 2 h or 365 μg/m32 h/d for 5 d did not significantly affect this parameter. Upper airway response, as measured by changes in hamster tracheal ciliary beating frequency, was not affected by either a 3‐h combined exposure to 196 μg O3/m3and 847 μg H2SO4/m3or a 2‐h exposure to 458 μg ultrafine H2SO4/m3.

ISSN:0098-4108    

DOI:10.1080/15287398209530258

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Acute and subacute toxicity was studied in adult Sherman strain rats exposed to 4,4'‐and 2,2'‐dipyridyl. The single oral LD50 for 4,4'‐dipyridyl was 175 mg/kg in male and 172 mg/kg in female rats; for 2,2'‐dipyridyl it was 100 and 107 mg/kg, respectively.

ISSN:0098-4108    

DOI:10.1080/15287398209530259

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The mammalian acute and genetic toxicity of 1‐nitropyrene (NP) was studied because this and other nitroarenes are highly mutagenic toward bacteria and have been identified in emissions from combustion processes. A suspension of NP did not cause observable signs of acute toxicity and was not lethal when administered to male and female rats at single oral doses as high as 5.0 g/kg. Histological examination of stomach, intestine, lung, heart, spleen, pancreas, adrenal, and kidney from rats euthanized at 4 and 14 d after treatment revealed no detectable differences from control rats. Urine and feces were collected for 4 d after treatment with 5.0 g/kg. About 70% of the dose was present in the feces as NP, and about 2% was present as the reduced metabolite Uaminopyrene (AP). Sulfate and glucuronide conjugates of AP were present in small amounts (<1%) in the urine, showing that at least some of the dose was absorbed. Bone marrow cells from female rats given NP orally at 0.5, 1.5, and 5.0 g/kg showed a slight dose‐related increase in the frequency of sister chromatid exchanges. Both NP and AP showed low mutagenicity in Chinese hamster ovary cellsin vitro. Evidence of reductive metabolism of NP in rats raises concern about the potential exposure of humans to this compound. However, the weakin vivoandin vitrogenetic toxicity of NP at high dose levels in mammalian systems suggests that the potential hazard may not be as high as predicted from bacterial mutagenicity data.

ISSN:0098-4108    

DOI:10.1080/15287398209530260

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The toxicity of cyclohexanone, used as a solvent cement in polyvinyl chloride medical devices, was assessed in Wistar and Gunn rats. The Gunn rat was used because it has a negligible activity of UDP glucuronosyltransferase toward bilirubin and certain other aglycones. Cyclohexanone was administered iv for 28 consecutive days to Wistar and Gunn rats in two doses (50 and 100 mg/kg), using solutions containing 0.25 and 0.50 g per 100 ml, respectively, at a constant volume of 20 mg/kg. Saline (0.9% NaCI) was used as the control. Daily observations for signs of toxicity showed no adverse effects in Wistar or Gunn rats injected with either dose. Daily weight changes of control and test animals were similar. Ophthalmologic examinations revealed no treatment‐related structural lesions. No adverse effects were noted when the data from the hemogram or clinical chemistry parameters were evaluated. Gross pathological and histopathologic assessment showed no alterations due to cyclohexanone treatment. Urinary excretions of total and glucuronide conjugates of cyclohexanol were similar for Wistar and Gunn rats; less than 1% was excreted as free cyclohexanone and cyclohexanol. It is concluded that the Gunn rat is capable of forming glucuronides of cyclohexanol and that cyclohexanone at these doses has a negligible toxic potential.

ISSN:0098-4108    

DOI:10.1080/15287398209530261

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A dose‐dependent change was observed in the disposition of14C‐labeled ethylene glycol (EG) after iv administration of 20, 200, 1000, and 2000 mg/kg to Fischer 344 rats. The part of the dose expired as CO2decreased from 39% at 20 and 200 mg/kg to 26% at 1000 and 2000 mg/kg, while urinary excretion of radiocarbon increased from 35 to 56%. The increase in urinary14C was almost entirely attributable to [14C] glycolate, which comprised 20% of the dose in 24 h at the two higher dose levels and only 2% at the lower doses. High doses of EG limited the processes responsible for glycolate metabolism, supporting the idea that this acid is a major contributing factor to the acute toxicity of EG. Compensatory urinary excretion of glycolate resulted in minimal dose‐dependent effects on14C blood clearance. Blood clearance of14C occurred in an initial rapid phase (half‐life, 3–5 h), when plasma was comprised predominantly of ethylene glycol, that persisted for 12 h at 20 mg/kg EG and 30 h at 2000 mg/kg. The dose‐dependent profile of EG metabolism argues against the use of very high chronic doses in studies intended to estimate health risks of long‐term, low‐level exposure to EG.

ISSN:0098-4108    

DOI:10.1080/15287398209530262

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Macrobenthic animal communities, developed in sand‐filled aquaria in the laboratory and in the field, were exposed to various concentrations of the insecticide chiorpyrifos, and effects on community structure were assessed. Laboratory communities were continuously exposed to the toxicant for 8 wk during colonization by planktonic larvae in unfiltered Santa Rosa Sound, Fla., seawater. Field communites were developed for 8 wk in aquaria placed in Santa Rosa Sound, then removed to the laboratory for exposure to chiorpyrifos for one week. Abundance of arthropods was significantly diminished (α = 0.05) by measured concentration of chiorpyrifos ≥ 0.1 μg/l in water in laboratory communities and by 5.9 μg/l in water in field communities. Numbers of annelids and chordates in contaminated aquaria were not reduced by the highest concentrations of chlorpyrifos tested, 8.5 μg/1 in laboratory‐colonized aquaria and 5.9 μg/l in field‐colonized aquaria. One species of annelid,Cistenides gouldii, was more abundant in field aquaria receiving 1.0 μg/l or 5.9 μg/I than in the control and lowest concentration. Molluscan larvae colonizing laboratory aquaria were sensitive to ≥ 0.1 μg/l; however, later developmental stages characterizing field aquaria were not sensitive to ≤ 5.9 μg/l. Although only 20 of 78 animal species appeared in both laboratory and field communities, sensitivity of animals in these tests and in single species tests could be compared.

ISSN:0098-4108    

DOI:10.1080/15287398209530263

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Cigarettes prepared from tobacco grown on municipal sludge‐amended soil were smoked, and the mainstream particulates and gaseous fractions were analyzed for total cadmium and nickel content. Sludge‐grown and control (soil‐grown) tobaccos contained, respectively, 67.4 and 3.18 ppm of cadmium and 19.4 and 1.29 ppm of nickel. The quantities of cadmium (μg per cigarette) found in the mainstream paniculate and gaseous fractions were, respectively, 6.67 and 0.04 for the sludge‐grown and 0.21 and 0.03 for the control treatments. The quantities of nickel (μg per ciagrette) found in the mainstream particulates and gaseous fractions were, respectively, 0.11 and 0.07 for the sludge‐grown and 0.01 and 0.01 for the control treatments. The potential public health implications of these results and modifying factors are discussed.

ISSN:0098-4108    

DOI:10.1080/15287398209530264

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Skin allograft rejection and isograft acceptance was studied in Balb/c mice exposed to 0, 0.01, 0.1, 1.0, or 10.0 ppm cadmium in drinking water beginning 4 wk prior to grafting. Cadmium exposure was associated with a dose‐dependent acceleration of the rejection of allografts prepared from the tail skin of C57/BL mice. The mean time to allograft rejection decreased from 10.4 d in non‐metal‐exposed recipients to 7.4 d in mice exposed to 10 ppm cadmium. Cadmium exposure was also associated with a dose‐dependent increase in the time to isograft acceptance (8.6 d in control mice compared to 11.0 d in mice exposed to 10 ppm cadmium). In addition, some isografts were rejected by animals exposed to 1 or 10 ppm cadmium. It is suggested that a cadmium‐induced modification of the wound‐healing process could explain both the allograft and isograft response, although an effect of cadmium on the immune response to histoincompatible tissue may also play a role in the accelerated allograft rejection.

ISSN:0098-4108    

DOI:10.1080/15287398209530265

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

To examine the effects of dietary fat on the levels of lead in the blood, 34–40‐d‐old male mice were fed normal or high‐fat diets along with distilled water for an initial 48‐h exposure period. Following this session, subjects from each diet condition were administered either 0, 0.075, or 0.5% lead acetate through the drinking water during the next 48 h along with their respective diets. Atomic absorption was used to analyze blood‐lead levels. At each concentration of lead, the high‐fat diet increased the blood lead content over subjects fed the control diet. The highest blood lead levels were found in the 0.5% lead acetate, high‐fat diet condition. The importance of nutritional considerations in understanding lead toxicity is discussed.

ISSN:0098-4108    

DOI:10.1080/15287398209530266

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Gravid female mice received either a single subcutaneous dose of cerium citrate (80 mg Ce/kg) or an equivalent (in citrate) dose of sodium citrate on d 7 or 12 of gestation or on d 2 postpartum. To separate effects of prenatal and postnatal exposure, a cross‐fostering design was employed. The weight and gross activity of the neonates were assessed on d 8 or 13 postpartum. Open‐field behavioral parameters, accelerating rotarod performance, and passive avoidance learning were assessed on d 60–65 postpartum. Maternal offspring retrieval latency was measured on d 3 postpartum. Analyses revealed that neonatal weight was reduced both in offspring exposed to Cein uteroand in the offspring of mothers receiving Ce during lactation/suckling. Ce also appeared to affect maternal/offspring interaction: pups exposed prenatally to Ce were retrieved in less time than control pups. Except for an increased frequency of rearings in the open field of adult offspring exposed to Cein utero, Ce exposure had no apparent effect on behavioral parameters, either in neonatal or adult offspring.

ISSN:0098-4108    

DOI:10.1080/15287398209530267

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor