Subchronic (13-week) inhalation toxicity study of formaldehyde in male rats: 8-hour intermittent versus 8-hour continuous exposures

Wilmer, J.W.G.M.; Woutersen, Ruud; Appelman, L.M.; Leeman, Winfried; Feron, V.J.

doi:10.1016/0378-4274(89)90147-1

Cited by 59 publications

(32 citation statements)

References 7 publications

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“…In contrast to our findings, exposure of rats to 2 ppm in the study of Wilmer et al, (1989) and exposure to 1 ppm in the study of Zwart et al showed no histophatologic effects in nasal mucosa.…”

Section: Discussioncontrasting

confidence: 56%

Histopathologic Changes of Rat Tracheal Mucosa Following Formaldehyde Exposure

et al. 2005

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SUMMARY:Formaldehyde is a chemical, which is used traditionally for fixing the cadaver. It is vaporized during dissection and practical studying on cadaver. Studies show that this vapor can cause some clinical symptoms such as throat, eye, skin and nasal irritation.This study was designed to determine the histopathologic changes of rat tracheal mucosa while all of the experiments were exposed to formaldehyde for 18 weeks. This study was performed on 28, 6-7 weeks postnatal albino Wistar rats. The rats were divided into 3 case groups (E1: 4h/d, 4d/w; E2: 2h/d, 4d/w; E3: 2h/d, 2d/w) and 1 control group. The tracheal specimens were sectioned and stained with H&E technique for histopathologic study.An epithelial disorganization, cilia disappearance, slight dysplastic changes and slight subepithelial lymphocytic infiltration were observed in the case of E1. Epithelial disorganization, irregular cilia and slight subepithelial infiltration were seen in E2 and E3 groups. The results of this study show that "the more exposure to formaldehyde vapor, the more intense epithelial changes". 370In order to study the histopathologic changes in the tracheal respiratory mucosa, due to formaldehyde exposure in the dissection lab, and determining its relationship with the duration of exposure, this study was carried out on 28 Albino Wistar rats. MATERIAL AND METHODThis study was done on 28, 6-7 weeks postnatal Albino Wistar rats (bought from Iranian Pastor Institute), randomly divided into three equal case groups, based on the differences between exposure periods: E1 (4h/d, 4d/w), E2 (2h/d,4h/w), E3(2h/d,2d/w) and a control group without any exposure.Using a digital scale, the mean weights for each group were 252g (E1), 209g (E2) and 222g (E3) and 195g (control group). The concentration of formaldehyde vapor was measured at the beginning, during and at the end of the study by means of Detector Tube and Dragger Pump (model 31, made in Germany) after the covers of the cadavers were removed. The vapor concentration of dissection room was 1-1.5 ppm when the air-conditioner was ON and 1.5-1.9 ppm when it was OFF. The temperature of dissection room was 20-26 ˚C and the air pressure was 760-763 atm.At non-exposure times, all groups were kept in laboratory animal house, which was far from the place of exposure with no formaldehyde detection. The animal house was ventilated and its temperature was kept around 21ºC with air conditioner system and adequate light was prepared. All groups were fed with a standard similar diet (bought from Iranian Pastor Institute) two times a day (morning and afternoon); but water was available all the time (ad libitum). The cages of the case groups were placed at a height the same as cadaver's height with a distance of 15cm apart from them for 18 weeks, corresponding time protocols mentioned above. During each period of exposure, the control group was kept in the animal house.When the exposure period was expired, each of the rats of both experiments and control groups were anaesthetized with chloroform. After...

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Section: Discussioncontrasting

confidence: 56%

Histopathologic Changes of Rat Tracheal Mucosa Following Formaldehyde Exposure

et al. 2005

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“…Short-term (4-week) formaldehyde exposure, on the other hand, induces cytotoxicity in the respiratory epithelium (26). After 3 days of exposure to 6, 10, 15 or 20 ppm formaldehyde, an increase in cell replication rate is evident in the respiratory epithelium lining the anterior portion of the naso-and maxilloturbinates (26,27).…”

Section: Metabolism Of Inhaled Estersmentioning

confidence: 99%

“…After 3 days of exposure to 6, 10, 15 or 20 ppm formaldehyde, an increase in cell replication rate is evident in the respiratory epithelium lining the anterior portion of the naso-and maxilloturbinates (26,27).…”

Section: Metabolism Of Inhaled Estersmentioning

confidence: 99%

Biotransformation Enzymes in the Rodent Nasal Mucosa: The Value of a Histochemical Approach

Bogdanffy¹

1990

Environmental Health Perspectives

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An increasing number of chemicals have been identified as being toxic to the nasal mucosa of rats. While many chemicals exert their effects only after inhalation exposure, others are toxic following systemic administration, suggesting that factors other than direct deposition on the nasal mucosa may be important in mechanisms of nasal toxicity. The mucosal lining of the nasal cavity consists of a heterogeneous population of ciliated and nonciliated cells, secretory cells, sensory cells, and glandular and other cell types. For chemicals that are metabolized in the nasal mucosa, the balance between metabolic activation and detoxication within a cell type may be a key factor in determining whether that cell type will be a target for toxicity. Recent research in the area of xenobiotic metabolism in nasal mucosa has demonstrated the presence of many enzymes previously described in other tissues. In particular, carboxylesterase, aldehyde dehydrogenase, cytochromes P-450, epoxide hydrolase, and glutathione S-transferases have been localized by histochemical techniques. The distribution of these enzymes appears to be cell-type-specific and the presence of the enzyme may predispose particular cell types to enhanced susceptibility or resistance to chemical-induced injury. This paper reviews the distribution of these enzymes within the nasal mucosa in the context oftheir contribution to xenobiotic metabolism. The localization of the enzymes by histochemical techniques has provided important information on the potential mechanism of action of esters, aldehydes, and cytochrome P-450 substrates known to injure the nasal mucosa.

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“…In comparison, in this study IC 50 values for in vitro toxicity of formaldehyde in A549 cells and HepG2 cells were found to be 524±105 ppm and 305±84 ppm respectively. In vivo published data suggest that the cytotoxic effects of formaldehyde in laboratory animals appears to be more closely related to the exposure level of formaldehyde than to the time of exposure or total dose [20,21].…”

Section: Discussionmentioning

confidence: 99%

Toxicity of volatile organic compounds (VOCs) mixtures using human derived cells

Khalil¹,

Nasir²

2010

WIT Transactions on Ecology and the Environment

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Assessing the effects of contaminants is an issue of high priority for governmental safety health and environmental agencies around the world. The general conservative consensus is that chemicals in mixtures interact by concentration addition. However, previous studies also report that concentration addition of mixture components does not always reflect the overall toxicity of a mixture. Volatile organic compounds (VOCs) such as Benzene, Toluene, Xylene and Formaldehyde (BTXF) belong to the air pollutants found in urban and indoor environments. They could trigger acute and chronic adverse health effects like allergy, respiratory and cardiovascular diseases. The volatile nature of these compounds poses additional problems in assessing individual volatile chemical toxicity let alone mixtures of these chemicals. Our research aims at establishing the true toxic effects of VOC exposure in vitro using a static direct exposure glass-chamber method. This was achieved by assessing and comparing individual and interactive effects of VOCs in exposed human epithelial lung (A549) and liver cells (HepG2) using the MTS cytotoxicity assay to assess cell viability upon VOC insult. The study results clearly indicated the limitation of the concentration addition method used in assessing volatile mixtures cytotoxicity and the need to develop new techniques for rapid and accurate mixture toxicity determination. The study may have implications for regulatory risk assessment of environmental volatile organic chemicals.

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Subchronic (13-week) inhalation toxicity study of formaldehyde in male rats: 8-hour intermittent versus 8-hour continuous exposures

Cited by 59 publications

References 7 publications

Histopathologic Changes of Rat Tracheal Mucosa Following Formaldehyde Exposure

Histopathologic Changes of Rat Tracheal Mucosa Following Formaldehyde Exposure

Biotransformation Enzymes in the Rodent Nasal Mucosa: The Value of a Histochemical Approach

Toxicity of volatile organic compounds (VOCs) mixtures using human derived cells

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