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PubMed2006

Behavior of rock wool in rat lungs after exposure by nasal inhalation.

To evaluate the safety of rock wool (RW) fibers, we examined the biopersistence of RW fibers in the lungs of rats, based on the changes of fiber number and fiber size in the length and width, in a nose-only inhalation exposure study. Twenty male Fischer 344 rats (6 to 10 wk old) were exposed to RW fibers at a fiber concentration of 70.6 (20.4) fiber/m(3) and a dispersion density of 30.4 (6.6) mg/m(3) [arithmetic mean (SD)] continuously for 3 h daily for 5 consecutive days. Five rats each were sacrificed shortly after exposure ended (baseline group) and at 1, 2, and 4 wk after exposure, and their lung tissues were ashed by a low temperature plasma-asher. The numbers and sizes of fibers in the ash samples were determined using a phase contrast microscope and a computed image analyzer. The fiber numbers in the lungs at 4 wk after exposure had significantly decreased from the baseline value, i. e. shortly after exposure (p<0.05). The half-lives of RW fibers calculated using the one-compartment model were 32 d for total fibers and 10 d for fibers longer than 20 microm in length. Fiber number was 53.6% of the baseline at 4 wk after exposure (baseline group=100%). Likewise, fiber sizes had significantly decreased at 4 wk after exposure (p<0.05), probably because fibers had been dissolved in body fluid, phagocytosed by alveolar macrophages or discharged from the body by mucociliary movement. In future studies, it will be necessary to examine the carcinogenicity of RW fibers through long-term inhalation studies.

Animals↗
PubMed1991

Inhalation anaesthetics--exposure and control during veterinary surgery.

Results are reported for air sampling surveys carried out by the Health and Safety Executive (HSE) in 14 veterinary surgeries. For all personnel the geometric mean (GM) time-weighted average (TWA) exposures to halothane and nitrous oxide over the working period were 2.6 ppm (range: less than 0.5 119 ppm) and 100 ppm (range: 14-1700 ppm), respectively. Since surgery rarely lasted for more than 4 h the corresponding GMs for 8-h TWAs were lower, being 1.3 ppm (range: less than 0.5-34 ppm) for halothane and 34 ppm (range: 5-530 ppm) for nitrous oxide. The GM exposures of veterinarians and nurses were very similar. The size of the practice and the use of scavenging were significant factors in determining personal exposures to inhalation anaesthetics: by comparison general ventilation had little effect. The results are compared with earlier data from human surgery, and previous studies of exposure to inhalation anaesthetics during veterinary surgery are briefly reviewed.

Anesthesia, Inhalation↗
PubMed1989

Inhalation anaesthetics--exposure and control: a statistical comparison of personal exposures in operating theatres with and without anaesthetic gas scavenging.

Results are reported for air sampling surveys undertaken by the Health and Safety Executive (HSE) from 1980 to 1984 using diffusive samplers in 40 operating theatres and 18 recovery areas at 27 hospitals. For all personnel the geometric mean time-weighted average exposure to nitrous oxide in unscavenged theatres was 94 ppm and in scavenged theatres 32 ppm; the corresponding means for halothane were 1.7 and 0.7 ppm, respectively. Intermittent use of scavenging led to mean exposures between those found in scavenged and unscavenged conditions. Anaesthetists showed higher mean exposures than other staff in all conditions. Statistical analysis of the data demonstrates that mean exposures of operating theatre staff were significantly lower in scavenged than in unscavenged theatres. For most staff, exposure was also significantly lower in theatres using active scavenging systems compared with those using passive systems. The literature on the hazards of chronic exposure to inhalation anaesthetics and previous studies of exposure is also briefly reviewed.

Air Pollutants↗
PubMed1983

Reaction of rat lungs to inhaled chrysotile asbestos following acute and subchronic exposures.

Inhalation of asbestos fibers can cause fibrotic and neoplastic diseases in the lung. The early in vivo interactions between fibers and lung tissue that initiate these diseases have received little study. Male and female Fischer 344 rats were placed in inhalation chambers and exposed to 9.06 +/- 1.83 mg/m3 (average respirable mass) of chrysotile asbestos for 1 hr, 1 day, 7 hr/day for 5 days, or 5 days/week for 3 months. Qualitative examination of the tissue showed that, after 1 day, fibers were found not only in the alveolar macrophages, but also in the epithelium and interstitium of the alveolar region. After 3 months, numerous fibers were present in the epithelium and interstitium. Morphometric analysis of this tissue showed that these compartments were also the most significantly changed as a result of asbestos exposure. The majority of epithelial changes were attributable to a 57% increase in the number of type II cells and a 90% increase in their average cell volume. The interstitial cell population increased 58% with a 40% increase in the average cell volume. There was no significant increase in the volume of noncellular interstitium. A morphologic characterization of the interstitial cells showed that interstitial macrophages accounted for almost the entire increase in this population and that 88% of the fiber-containing cells were macrophages. Several interstitial macrophages contained membrane-bound inclusions which were shown by x-ray energy spectrometry to be microcalcifications. They were composed of rings of calcium phosphate granules around asbestos fibers. These microcalcifications may indicate sublethal cell injury caused by the presence of asbestos fibers in the cell cytoplasm. Fibers which enter but do not kil alveolar cells may be an essential component for the pathogenesis of lung disease caused by asbestos inhalation.

Animals↗
PubMed1999

An electrophysiological analysis of rat ventral tegmental dopamine neuronal activity during acute toluene exposure.

Inhalant abuse is a common, potentially lethal, form of drug abuse. Although the putative psychotropic component of some popularly abused inhalants appears often to be the organic solvent toluene, its effects on midbrain neurones which comprise reward pathways have not been established. Therefore, the present study was designed to assess the response of ventral tegmental dopamine neurones during toluene inhalation. Electrophysiological determinations were made using extracellular single-unit recordings in ketamine anaesthetized rats that were exposed to acute (1-15.3 min.) concentrations of toluene vapor (11,500 ppm) similar to those consumed by inhalant abusers. Toluene exposure through a tracheal breathing tube elicited two distinctly different patterns of response in dopamine neurons. One pattern consisted of an initial stimulation of neuronal firing (+221%+/-72%; <8.5 min.) followed by an attenuation of the firing rate with continued exposure (+58.7%+/-6.3%; >8.5 min.). The other pattern consisted of only an inhibition of firing regardless of the length of exposure. Furthermore, the changes in firing rates were paralleled by changes in number of action potentials contained in bursts. Blood samples taken at the time of the dopamine recordings revealed comparable toluene concentrations (4-79 microg/ml, n=24) regardless of the patterns of response. These results suggest that mesolimbic dopamine neurotransmission can be changed by an exposure paradigm comparable to that used by human abusers, and that these changes may be integral to the reinforcing effects underlying inhalant abuse.

Action Potentials↗
PubMed2000

Th2 responses induced by epicutaneous or inhalational protein exposure are differentially dependent on IL-4.

Atopic individuals are predisposed to mounting vigorous Th2-type immune responses to environmental allergens. To determine the factors responsible, animal models that closely mimic natural modes of allergen exposure should prove most informative. Therefore, we investigated the role of IL-4, a known Th2-promoting cytokine, in generation of Th2 responses after exposure of either the skin or airway to soluble protein. Compared with wild-type (WT) mice, IL-4-deficient (IL-4(-/-)) mice showed markedly impaired Th2 activation after primary exposure to inhaled ovalbumin (OVA), with decreased OVA-specific IgG1 and IgE, and significantly fewer eosinophils in bronchoalveolar lavage (BAL) fluid after airway challenge. In contrast, IL-4(-/-) mice initially exposed to epicutaneous (e.c.) OVA mounted Th2 responses equivalent to responses in WT mice, with high numbers of eosinophils in BAL fluid. Because Th2 responses were not induced by e.c. OVA exposure in Stat6(-/-) mice (mice lacking signal transducer and activator of transcription 6), the role of IL-13 was tested. In vivo depletion of IL-13 prevented Th2 responses induced by e.c. OVA exposure in IL-4(-/-) mice. These data demonstrate a marked difference in the IL-4 dependence of Th2 responses generated at two anatomic sites of natural allergen encounter and identify the skin as a particularly potent site for Th2 sensitization.

Administration, Cutaneous↗
PubMedDate not supplied

[Proposal of environmental and biological monitoring and health surveillance of the exposed to inhalation anesthetics. Consensus. A Study Group on Occupational Exposure to Inhalation Anesthetics].

The Study Group on Occupational Exposure to Inhalation Anaesthetics of the Lombardy Association of Occupational Health and Industrial Hygiene prepared a document that was discussed during the Congress "Occupational Risks due to Inhalation Anaesthetics", held in Brescia, Italy, on May 12, 1992. The same document was then approved by the Directory Council of the Lombardy Association of Occupational Health and Industrial Hygiene. Data on environmental concentrations of Nitrous Oxide collected from 1989 to 1991 in 269 operating rooms of 47 hospitals in Lombardy are reported. The measured levels are considerably lower than those collected from the same Study Group from 1985 to 1987 in 111 operating rooms. The methodologies for exposure control are discussed, regarding both environmental and biological monitoring. These two techniques are complementary and can be used with standardized methods. The review of the literature on the early effects showed, even with some uncertainty at the current exposure levels, effects on liver and Central Nervous System. Still controversial are the data regarding the reproductive toxicity. Health surveillance programs have been organized in the last 5 years in 18 Lombardy hospitals and they indicate no cases of pathologies due to inhalation anesthetics on 1498 subjects. Operative proposals are suggested on the methodology and the frequency of environmental/biological monitoring and health surveillance. The "technical limit values" reported in the document from the Italian Ministry of Health are also discussed. Finally, research topics are suggested in order to assess the early effects of exposure.

Anesthesia, Inhalation↗
PubMed1997

The ototoxicity of trichloroethylene: extrapolation and relevance of high-concentration, short-duration animal exposure data.

Inhalation exposure to high concentrations of 1,1, 2-trichloroethylene (TCE) has been shown to damage hearing in the mid-frequency range in the rat. The present study directly evaluated the adequacy of high-concentration, short-term exposures to TCE for predicting the neurotoxicity produced by longer duration exposures. Adult male Long-Evans rats (n = 10-12 per group) were exposed to TCE via inhalation (whole body) in 1-m3 stainless steel flow-through chambers for 6 hr/day, 5 days/week. The following exposures were used: 1 day (4000-8000 ppm), 1 week (1000-4000 ppm), 4 weeks (800-3200 ppm), and 13 weeks (800-3200 ppm). Air-only exposed animals served as controls. Auditory thresholds were determined for a 16-kHz tone 3-5 weeks after exposure using reflex modification audiometry. Results replicated previous findings of a hearing loss at 16 kHz for all exposure durations. The dB15 concentrations (concentration that increases thresholds by 15 dB) for 16-kHz thresholds were 6218, 2992, 2592, and 2160 ppm for the 1-day, 1-week, 4-week and 13-week exposures, respectively. These data demonstrate that the ototoxicity of TCE was less than that predicted by a strict concentration x time relationship. These data also demonstrate that simple models of extrapolation (i.e., C x t = k, Haber's Law) overestimate the potency of TCE when extrapolating from short-duration to longer-duration exposures. Furthermore, these data suggest that, relative to ambient or occupational exposures, the ototoxicity of TCE in the rat is a high-concentration effect.

Administration, Inhalation↗
PubMed2004

Chronic inhaled ovalbumin exposure induces antigen-dependent but not antigen-specific inhalational tolerance in a murine model of allergic airway disease.

Sensitized mice acutely challenged with inhaled ovalbumin (OVA) develop allergic airway inflammation, characterized by OVA-specific IgE production, airway eosinophilia, increased pulmonary B and T lymphocytes, and airway hyperreactivity. In this study, a chronic exposure model was developed and two distinct patterns of response were observed. Discontinuous inhalational exposure to OVA (6 weeks) produced airway inflammation and hyperreactivity that were similar to acute (10 days) responses. Continuous inhalational exposure to OVA (6 or 11 weeks) resulted in attenuation of airway eosinophilia and hyperresponsiveness without reduction of OVA-specific IgE and IgG(1) levels. The inhibition of airway inflammation was dependent on continuous exposure to antigen, because continuously exposed mice with attenuated inflammatory responses redeveloped allergic airway disease if the OVA aerosols were interrupted and then restarted (11-week-discontinuous). Inhalational tolerance induced by continuous OVA exposure demonstrated bystander suppression of cockroach allergen-mediated airway eosinophilia. These findings may be attributed to changes in production of the anti-inflammatory cytokine interleukin-10 during continuous OVA aerosol exposure. The symptomatic and asymptomatic allergic responses in human asthmatics could be explained by similar variable or discontinuous exposures to aeroantigens.

Administration, Inhalation↗
PubMed2003

Determination of potential dermal and inhalation operator exposure to malathion in greenhouses with the whole body dosimetry method.

One of the steps during the authorization process of plant protection products (PPP) in the European Union is to evaluate the safety of the operator. For this purpose, information on the probable levels of operator exposure during the proposed uses of the PPP is required. These levels can be estimated by using existing mathematical models or from field study data. However, the existing models have several shortcomings, including the lack of data for operator exposure levels during spray applications by hand lance, especially in greenhouses. The present study monitored the potential dermal and inhalation operator exposure from hand-held lance applications of malathion on greenhouse tomatoes at low and high spraying pressures. The methodology for monitoring potential exposure was based on the whole body dosimetry method. Inhalation exposure was monitored using personal air pumps and XAD-2 sampling tubes. For the monitoring of hand exposure, cotton gloves were used in two trials and rubber gloves in another three. The total volumes of spray solution contaminating the body of the operator were 25.37 and 35.83 ml/h, corresponding to 0.05 and 0.07% of the applied spray solution, respectively, in the case of low pressure knapsack applications and from 160.76 to 283.45 ml/h, corresponding to 0.09-0.19% of the spray solution applied, in the case of hand lance applications with tractor-generated high pressure. Counts on gloves depended on the absorbance/repellency of the glove material. The potential inhalation exposures were estimated at 0.07 and 0.09 ml/h in the case of low pressure knapsack applications, based on a ventilation rate of 25 l/min. Both potential dermal operator exposure (excluding hands) and potential inhalation exposure were increased by a factor of approximately 7 when the application pressure was increased from 3 to 18 bar in greenhouse trials with a tractor-assisted hand lance, the rest of the application conditions being very similar.

Agriculture↗
PubMed1999

Exposure to preservatives used in the industrial pre-treatment of timber.

OBJECTIVE: The research was to survey potential dermal exposure and inhalation exposure of operators to preservative fluids used in industrial timber pre-treatment. RESULTS: Surveys in 1996-98 produced 64 data points. These were taken from 54 sites, and involved 57 timber pre-treatment process operators. Of the data, 38 related to copper chromium arsenic preservative used in vacuum-pressure processes, 19 to solvent-based preservative in double vacuum processes and 7 to water-based preservative in double vacuum processes. Treatment cycle times, preservative concentrations, treatment load sizes and quantities of preservative used per cubic metre of timber are reported. Preservative deposition patterns were similar for all treatments, with about 90% on the legs, and most of the remainder on the arms and chest. The results are quoted as mg preservative preparation (as opposed to active substance), expressed as mg per treatment cycle and mg per minute. Water-based products in vacuum-pressure processes (38 data) showed potential dermal exposure in the range 547-132,000 mg per cycle with a median value 3960 mg per cycle (median cycle time 3 h). Water-based products in double vacuum processes (7 data) showed a range 59-8750 mg per cycle with a median value 4260 mg per cycle; and solvent-based products in double vacuum processes (19 data) showed a range 7.5-449 mg per cycle with a median value 119 mg per cycle (median cycle time 1 h for double-vacuum processes). Contamination of work clothing occurred in nearly all surveys, with around 10% penetration of the preservative as estimated by a sampling patch mounted inside the operator's coveralls. Contamination was measured inside the operator's gloves in nearly all surveys. Wearing fresh gloves was found to reduce exposure to arsenic by 71% and to permethrin by 37%. Contamination on socks was measured and found to be less frequent for double vacuum than for vacuum-pressure processes. Exposure by inhalation for vacuum-pressure processes expressed as preservative, showed a range of 0.06-7.96 mg/m3, with a median value of 1.07 mg/m3, time-weighted average exposure over one or two treatment cycles. Exposure was detected in 68% of the vacuum-pressure process surveys. There was evidence for aerosol generation on transporting timber treated with water-based preservative. For double vacuum processes, two non-zero results only were found, both for water-based preservatives. Aerosols within treatment vessels were found to have dispersed 2.5 min after opening the door. Pilotstudy biological monitoring data for urinary chromium, arsenic, and permethrin metabolites are quoted with reference to creatinine. There are tentative conclusions relating to up take via the skin.

Agrochemicals↗
PubMed1976

Measurement and reduction of occupational exposure to inhaled anaesthetics.

The occupational exposure of hospital staff to inhaled anaesthetics was investigated using a personal sampling device that provides a measure of the average concentrations breathed by a person over a period of time, as distinct from the spot sampling in the general environment. The anaesthetist's average exposure to nitrous oxide and halothane during complete operating sessions was twice that expected from simple dilution of the escaping gases by the operating room ventilation. The sampling technique was also used to evaluate the effect of (1) redirection of the waste gas outflow; (2) active scavenging connected to the piped vacuum system. Short-period studies under controlled conditions in the operating theatres and anaesthesia induction rooms showed that the anaesthetist's exposure could be reduced two- or fourfold by redirecting the outflow and another four- to sixfold by active scavenging. Exposures during complete operating sessions were reduced two- to seven-fold by scavenging.

Air Pollutants↗
PubMed2000

Trends in exposure to inhalable particulate and dermal contamination in the rubber manufacturing industry: effectiveness of control measures implemented over a nine-year period.

Exposure to inhalable particulates and dermal exposure to cyclohexane soluble matter (CSM) were evaluated in seven rubber manufacturing companies in 1988 and 1997. The identified exposure trends were used to study the effectiveness of control measures implemented over a nine-year period. Sampling and analytical methodologies were identical in both surveys. Inhalable particulate exposure was measured with a PAS6 sampling head. Dermal exposure was assessed by means of a dermal pad sampler worn at the lower wrist of the hand of preference. Changes in working organization and control measures taken after 1988 were identified based on discussions with management representatives and two walk-through surveys performed in 1994 and 1997. Exposure data were aggregated for comparison between years both at company and production function level. The mixed effect statistical procedure was used to evaluate the influence of control measures and seniority on current exposure levels. Comparison of the exposure levels between 1988 and 1997 revealed a reduction rate of 5.7 and 6.7% per year for inhalable particulate and dermal exposure, respectively. Companies and production functions with the highest exposure levels in 1988 and workers with seniority (more experience) showed a steeper decline in exposure levels. Fifty-seven control measures, mostly designed to control the levels of inhalable exposure were identified. Elimination of sources significantly reduced the inhalable particulate and dermal exposure by two-thirds of the level of 1988. Reduction of emission did not show a significant overall decrease in exposure concentrations. Control measures designed to control the levels of contaminants showed a significant reduction for both inhalable and dermal exposure, respectively 34 and 49% of the exposure level of 1988. These results indicate that efforts taken to improve work conditions in the rubber manufacturing industry in The Netherlands over this decade have been successful in reducing both inhalable particulate and dermal contamination.

Air Pollutants, Occupational↗
PubMed2001

Toxicokinetics of ethers used as fuel oxygenates.

The toxicokinetics and biotransformation of methyl-tert.butyl ether (MTBE), ethyl-tert.butyl ether (ETBE) and tert.amyl-methyl ether (TAME) in rats and humans are summarized. These ethers are used as gasoline additives in large amounts, and thus, a considerable potential for human exposure exists. After inhalation exposure MTBE, ETBE and TAME are rapidly taken up by both rats and humans; after termination of exposure, clearance by exhalation and biotransformation to urinary metabolites is rapid in rats. In humans, clearance by exhalation is slower in comparison to rats. Biotransformation of MTBE and ETBE is both qualitatively and quantitatively similar in humans and rats after inhalation exposure under identical conditions. The extent of biotransformation of TAME is also quantitatively similar in rats and humans; the metabolic pathways, however, are different. The results suggest that reactive and potentially toxic metabolites are not formed during biotransformation of these ethers and that toxic effects of these compounds initiated by covalent binding to cellular macromolecules are unlikely.

Air Pollutants↗
PubMed2001

Workshop on harmonization of serving future needs with occupational exposure databases--inhalation modeling, session IIIA.

This workshop was one of several that took place at the International Symposium on Occupational Exposure Databases and Their Application for the Next Millennium held in London from November 1-3, 1999. About 30 delegates participated in the workshop. The agenda for the discussions was provided by a white paper prepared by the organizers. The workshop produced a conceptual outline for a general-purpose prediction model for inhalation exposure, and constructed a list of important input variables for successful model development. Evaluation of prototype models was discussed in some detail, and the workshop concluded with suggestions for taking forward the ideas discussed and maintaining the momentum and interest generated during the symposium.

Databases, Factual↗
PubMed2004

Exposure to inhalable dust, wheat flour and alpha-amylase allergens in industrial and traditional bakeries.

This study was designed to characterize exposure to inhalable dust, wheat flour and alpha-amylase allergens in industrial and traditional bakeries. The study included 70 bakeries from the northern part of Belgium. Based on the degree of automation and a clear division of individual job tasks, four bakeries were identified as industrial and the remaining 66 were identified as traditional ones. Personal, as well as stationary, samples of inhalable dust were collected during full shift periods, usually 5-7 h. The portable pumps aspirated 2 l/min through Teflon personal dust samplers (Millipore, pore size 1.0 microm) mounted in PAS-6 sampling heads. In the collected samples the inhalable dust, wheat flour and alpha-amylase allergens were determined. Wheat flour allergens were measured using enzyme-linked immunosorbent assay inhibition and an antiwheat IgG4 serum pool. The alpha-amylase allergens were measured using a sandwich enzyme immunoassay with affinity-purified polyclonal rabbit IgG antibodies. In total, 440 samples (300 personal and 140 stationary) were processed. The highest inhalable dust exposure was observed in traditional bakeries among bread [geometric mean (GM) 2.10 mg/m3] and bread and pastry workers (GM 1.80 mg/m3). In industrial bakeries the highest dust exposure was measured in bread-producing workers (GM 1.06 mg/m3). Similar relations were observed for wheat flour and alpha-amylase allergens. Bread baking workers in traditional bakeries had the highest exposure to both allergens (wheat flour GM 22.33 microg/m(3), alpha-amylase GM 0.61 ng/m3). The exposure to wheat flour and alpha-amylase allergens in industrial bakeries was higher in bread baking workers (wheat flour GM 6.15 microg/m3, alpha-amylase GM 0.47 ng/m3) than in bread packing workers (wheat flour GM 2.79 microg/m3, alpha-amylase GM 0.15 ng/m3). The data presented suggest that, on average, exposure in the Belgium bakeries studied-industrial as well as traditional-is lower than or similar to bakeries in The Netherlands, Canada, Sweden, the United Kingdom and Finland. Furthermore, the exposure levels in traditional bakeries seem to be higher than in industrial bakeries.

Allergens↗
PubMed2002

Quantification of respirable, thoracic, and inhalable quartz exposures by FT-IR in personal impactor samples from construction sites.

The classification of quartz as a group I human carcinogen by the International Agency for Research on Cancer (IARC) highlights the need to develop a method to assess quartz exposures in the thoracic and inhalable particle size fractions to supplement the current method for the respirable size fraction. Heavy and highway construction operations can produce high respirable quartz exposures, but inhalable and thoracic exposures have not previously been well characterized. These larger particle size fractions may well contribute to the elevated cancers of the buccal cavity, throat, and GI tract in occupational cohorts of construction workers. A description is provided of the application of FT-IR for quartz analysis of personal cascade impactor air samples collected from highway construction sites. Separate calibration curves were generated for each stage of the four-stage personal impactor by using the impactor to sample quartz dust (Min-U-Sil 5 and Min-U-Sil 30) in an aerosol-generating loop. In addition, three separate calibration curves were generated using filters spiked with bulk Min-U-Sil 5, Min-U-Sil 30, and SRM 1878a (a respirable standard from NIST). The results showed that bulk Min-U-Sil 5 and SRM 1878a calibrations were identical and accurately estimated the respirable quartz fraction. Bulk Min-U-Sil 30 underestimated quartz in stages 1, 2, and 3 by 46 percent, 38 percent, and 18 percent, respectively. Using a respirable standard (bulk Min-U-Sil 5 or SRM 1878a) to quantify the larger particle sizes underestimated quartz in stages 1, 2, and 3 by 73 percent, 72 percent, and 63 percent, respectively. Until a standard reference material for quartz is developed for the larger particle sizes, the method described here, with some modifications, can be used to provide estimates of these biologically relevant particle size fractions. The results of this study also reaffirmed the need to collect narrow ranges of particle size in order to minimize quantification errors, since the FT-IR and XRD instrumental response is particle size-dependent.

Air Pollutants, Occupational↗
PubMed1998

Exposure to captan in fruit growing.

This study characterized occupational exposure to pesticides in fruit growing in The Netherlands to assess determinants of exposure. Large-scale exposure surveys were carried out during application of pesticides and during reentry activities. Data on contamination inside the fruit growers' homes were obtained, and total potential exposure for the fruit grower and his family during the growing and harvesting season was estimated. Repeated measurements on the same subject were collected to study components of exposure variability. Relative contribution of the respiratory route and different skin sites to total exposure were assessed. Captan was used as a marker for exposure. Inhalable dust exposure was measured with a personal monitor and potential dermal exposure with skin pads and hand rinsing. Dislodgeable foliar residue was measured by taking leaf punches. For respiratory exposure and potential dermal exposure, differences were observed between several tasks. Workers were categorized according to tasks performed depending on the exposure measure(s) (e.g., hands, forehead, inhalable dust) considered relevant for a specific study purpose. In general, within-worker variability of all exposure measurements was larger than between-worker variability. Variability in dermal exposure on the same body location was small relative to variability between different body locations. Differences in total exposure, including exposure inside the home, between the fruit grower and the son were small. Exposure of the wife was two to three times lower than for the fruit grower and the son. As exposure per unit of time was in the same order of magnitude for different tasks, individual time spent on these tasks is crucial for estimating total potential exposure. Repeated measurements are necessary to estimate individual exposure accurately because of the large within-worker variability.

Adolescent↗