Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RUBBER”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources

Increased lymphocyte DNA strand breaks in rubber workers.

OBJECTIVE: To study the effect of occupational exposure to rubber processing, smoking, and alcohol drinking on lymphocyte DNA damage. SUBJECTS AND METHODS: Of 371 employees (197 men and 174 women) from a rubber factory in Guangzhou, 281 were rubber processing workers from five production sections and 90 were managerial workers. Information on occupational exposure, smoking, and drinking was collected by interviews. Blood samples were taken in the morning by venipuncture. DNA damages were measured by the Comet assay. Possible DNA-protein crosslinks were broken down by proteinase K. Tail moment, measured by Komet 4.0 image analysis software, was the measure of DNA damage. RESULTS: The rubber processing workers had larger tail moment than the managerial workers (Geometric mean, 95%CI) [1. 77microm (1.64-1.90) versus 1.52microm (1.36-1.71), P=0.04]. Both smoking [1.93microm (1.74-2.13) versus 1.59microm (1.47-1.71), P=0. 003] and alcohol drinking [2.21microm (1.87-2.62) versus 1.63microm (1.53-1.74), P<0.001] increased tail moment. Tail moment differed significantly among job categories (F=3.21, P=0.008), the largest was observed in mixers. In the non-smoking and non-drinking workers, rubber processing workers had larger tail moment than managerial workers after adjusting for age (P=0.033). General linear model analysis showed that after adjusting for each other, occupational exposure (P=0.027), smoking (P=0.012), and alcohol drinking (P=0. 013) was associated with larger tail moment, whereas age and gender had no effect. CONCLUSIONS: Occupational exposure to rubber processing, smoking, and alcohol drinking can cause DNA damage.

Comet Assay↗

Structure elucidation of an artifact discharging from rubber-based vial closures by means of gas chromatography/tandem mass spectrometry.

The use of vial closures equipped with butyl rubber septa may lead to sample contamination by rubber additives discharging from the septum material. In this study, the structure elucidation of an artifact causing intense signals in gas chromatography/electron capture negative ion mass spectrometry (GC/ECNI-MS) and gas chromatographic analyses with electron capture detection is described. Tentative identification of the leached compound was achieved by employing tandem mass spectrometric techniques both in electron capture negative ion and in electron ionization modes. The artifact could thus be characterized as 2-benzothiazolyl-N,N-dimethyl dithiocarbamate, which is a known vulcanization accelerator for rubber. It is conceivable that the identified compound or related substances are also used in other applications. Therefore, two food-related matrixes were investigated for a possible migration of this compound into foods. During these analyses, the tentatively identified rubber additive was detected in an aqueous extract of a rubber seal ring for canning jars. GC/ECNI-MS provided better sensitivity and selectivity than GC/EI-MS for the determination of the rubber additive and other mercaptobenzothiazole-derived substances.

Chromatography, Gas↗

Occupational exposure to commercial decabromodiphenyl ether in workers manufacturing or handling flame-retarded rubber.

Commercial decabromodiphenyl ether (DecaBDE) is commonly used as a flame retardant in different electrical and textile applications. It is also used in the production of flame-retarded rubber compound. DecaBDE is the major technical polybrominated diphenyl ether (PBDE) in use today and consists mainly of decabromodiphenyl ether (BDE-209). PBDEs, including BDE-209, are well-known environmental pollutants, ubiquitous both in aquatic and terrestrial environments. The aim of the present study was to assess the exposure to PBDEs in workers manufacturing or handling rubber which was flame retarded with DecaBDE. A referent group, abattoir workers (slaughterhouse workers), with no occupational exposure to PBDEs, was also investigated. Moreover, the methodology for analysis of PBDEs in serum was refined, with special emphasis on congeners with a high number of bromine substituents, i.e., octa- to decaBDEs. The highest BDE-209 concentration observed among the rubber workers was 280 pmol/g lipid weight (I.w.) (270 ng/g I.w.). The median concentration of BDE-209 among rubber workers was 37 pmol/g I.w. (35 ng/g I.w.). Among referents, the median was 2.5 (range 0.92-9.7) pmol/g I.w. (median 2.4 ng/g I.w.). In rubber workers the BDE-209 concentrations were up to 32% (median 4%) of the 2,2',4,4',5,5'-chlorobiphenyl (CB-153) concentrations, on a molar basis, whereas the referents had BDE-209 concentrations which were similar to that of 2,2',4,4'-bromodiphenyl ether (BDE-47), below 1.4% (median 0.3%) of the CB-153 concentration. Concentrations of all nonabromodiphenyl ethers (nonaBDEs) and several octabrmodiphenyl ethers (octaBDEs) congeners, including BDE-203, were also elevated among the rubber workers, with 2.5- to 11-fold higher median concentrations, compared to the referents. The results confirm a significant uptake of BDE-209 in the workers exposed to DecaBDE and indicate a potential for in vivo formation of lower BDEs in these persons.

Adult↗

Effect of rubber dam on mercury exposure during amalgam removal.

It was the aim of this investigation to treat 20 volunteers with maximally 5 amalgam fillings by the same comprehensive protocol in which all removals with (n = 8) and without (n = 12) rubber dam had been performed within a few months. Nine amalgam-related parameters indicated a close matching of both groups before removal. In the group without rubber dam, mercury (Hg) levels in plasma increased significantly above preremoval values at days 1 and 3 after removal; they decreased significantly below preremoval values at day 30 in the rubber-dam group and at day 100 in both groups. Excretion rates did not increase significantly in either group, but decreased significantly at day 100 in the protected group. Peak plasma-Hg was 0.6 ng/mL on average at day one and decreased with halftimes of 3 and 43 d in subjects protected by rubber dam. The results indicated that concentrations of total mercury in plasma responded rapidly to changes in the amalgam status and reflected the actual absorption most reliably. Notably, plasma-Hg levels were sensitive enough to detect a transient attenuation of the additional exposure by using rubber dam during the removal of only a few fillings. However, being small in magnitude and lasting 100 d at best, the rubber-dam effect had minor toxicological relevance.

Absorption↗

Occupational risk factors for mortality from stomach and lung cancer among rubber workers: an analysis using internal controls and refined exposure assessment.

OBJECTIVES: To determine occupational risk factors for stomach and lung cancer among workers in the German rubber industry. METHODS: A cohort of all male German rubber workers (n = 11,633) who had been employed for at least one year in one of five study plants and who were alive and actively employed or retired on 1 January 1981 was followed for mortality from 1 January 1981 through December 1991. A subcohort of n = 8,933 workers who were hired after 1 January 1950 was defined to focus on working conditions in the more recent rubber industry. Work histories were reconstructed using routinely documented 'cost centre codes' and classified into six work areas as well as subgroups of some work areas. The work areas are: 1. preparation of materials, 2. production of technical rubber goods, 3. production of tyres, 4. storage and dispatch, 5. maintenance, 6. others. Standardized mortality ratios (SMR) and Cox proportional hazards models were calculated for each of the work areas (>1 year of employment in the respective work area). Hazard rate ratios were adjusted for age (time marker) and stratified for year of hire (1950-1959, > or =1960) and years of employment in the respective work area (1-9 years, > or =10 years); years of employment were lagged 10 years to account for latency. RESULTS: Compared to the national reference population mortality from cancer of stomach (observed 44, SMR = 117; 95% CI: 85-157) and lung (observed 154, SMR = 123; 95% CI: 104-144) was slightly increased. Using internal controls we observed excess deaths from stomach cancer in work area 1 (relative risk [RR] = 2.3; 95% CI: 1.2-4.2) and from lung cancer in work areas 1 (RR = 1.7; 95% CI: 1.2-2.3), 2 (RR = 1.5; 95% CI: 1.1-2.1), and 3 (RR = 1.3; 95% CI: 0.9-1.8). On the basis of cumulative years of employment an exposure response relationship was observed for mortality from both cancer sites among a subcategory of work area 1: weighing and mixing. Increased risks were also seen for lung cancer among workers employed in production of technical rubber goods. CONCLUSION: Our results support an association between an excess mortality from stomach and lung cancer and employment in early production stages of rubber manufacturing, especially weighing and mixing. This may point to an aetiologic role of asbestos or carbon black. For stomach cancer additional risk factors, e.g. exposure to dust and talc, deserve further investigation. The results of the present study do not support a causal role of nitrosamines for stomach or lung cancer.

Case-Control Studies↗

Biocontrol Potential and Mechanism of Endophytic Bacillus velezensis WSR1 Against Rubber Tree Anthracnose.

Fungal leaf anthracnose, caused by Colletotrichum species, is a major leaf disease of rubber trees, significantly reducing global natural rubber yields. To explore sustainable and safe biological control strategies, eight bacterial strains were isolated from rubber tree tissues, demonstrating antagonistic activity against Colletotrichum pathogens (C. siamense and C. australisinense). Among these, WSR1 exhibited the most pronounced antifungal effect, with inhibition rates of 87.64 and 89.03% against C. siamense and C. australisinense, respectively. Genomic analysis identified WSR1 as Bacillus velezensis. In pot experiments, WSR1 exhibited preventive efficacy of 77.24 and 73.42% for C. siamense- and C. australisinense-induced anthracnose, respectively, with therapeutic efficacy of 42.28 and 45.57%. WSR1 compromised the integrity of the cell walls and membranes of both C. siamense and C. australisinense, while inducing reactive oxygen species accumulation within the hyphae. Additionally, WSR1 enhanced rubber tree resistance to anthracnose by activating defense-related enzymes, including phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase. Plate assays and genomic analysis revealed that WSR1 secretes fungal cell wall-degrading enzymes (cellulases, pectinases, and proteases) and siderophores. Furthermore, liquid chromatography-mass spectrometry and gene cluster analysis confirmed the synthesis of antagonistic secondary metabolites, such as surfactin, macrolactin H, and fengycin. This study represents the first identification of B. velezensis as a potential biocontrol agent against rubber tree anthracnose, offering a promising candidate for the eco-friendly management of rubber tree diseases.

C. australisinense↗

Immediate allergy to rubber gloves: a questionnaire study of hospital personnel.

We conducted a questionnaire study of immediate allergy to natural rubber gloves among 2,408 medical workers who had used rubber gloves at Kumamoto University Hospital and allied hospitals. The response rate was 64.5% (1,321 workers). Among them, 8.5% (7.0-10.0% at 95% confidence limit) replied that they had experienced immediate allergy to rubber gloves. There were significant correlations among the frequency of rubber glove use, a history of atopic dermatitis or contact dermatitis, and the presence of skin lesions due to allergic reactions to rubber gloves. In 27 workers, skin lesions were associated with general symptoms. Of 59 workers who experienced immediate allergy and were tested for latex-specific IgE, 4 persons were positive. We conclude that the frequency of contact allergy to natural rubber products is substantially prevalent among Japanese hospital personnel and that education and awareness of this allergy are important.

Dermatitis, Allergic Contact↗

An assessment of rubber dam usage amongst specialists in paediatric dentistry practising within the UK.

OBJECTIVE: Rubber dam is recommended by the British Society of Paediatric Dentistry (BSPD) for various restorative and endodontic procedures. To date, there has been no report of actual usage of rubber dam within the speciality of paediatric dentistry. The aim of this study was to assess the usage of rubber dam amongst paediatric dentistry specialists within the UK. METHODS: A postal questionnaire was distributed to all practitioners registered on the UK General Dental Council's 2004 specialist list in paediatric dentistry. RESULTS: Data were available for 162 questionnaires (a 75% response rate), and of these, 85% of respondents worked in the National Health Service (NHS), 4% were private practitioners and the remainder had a mixed NHS/private practice. Regarding the benefits of rubber dam, 65% and 52% of respondents quoted patient safety and moisture control, respectively. Perceived difficulties of dam usage were lack of patient cooperation and the non-necessity for a particular treatment, as quoted in 64% and 36% of the completed questionnaires, respectively. The most common modes of isolation for anterior and posterior teeth were Dry Dam(R) (58%), and clamp and dam (80%), respectively. CONCLUSION: Current BSPD guidelines recommend rubber dam usage for many restorative procedures; however, it would appear that there is wide variability in the application, as well as under-use, of rubber dam.

Adult↗

Discomfort from rubber gloves indicating contact urticaria.

Rubber glove intolerance is a common dermatological problem and hypersensitivity of both delayed and immediate types occur. In order to study immediate skin reactions induced by rubber gloves, 15 patients with discomfort and itch produced by rubber gloves were examined. The patients were provoked by wearing rubber gloves, scratch tested with gloves, rubber chemicals and powders. RAST-tests were performed using an extract from the rubber tree (Hevea brasiliensis). In 6/15 patients, contact urticaria was confirmed, in 3 of whom IgE antibodies to latex were demonstrated.

Adult↗

Contact urticaria due to rubber chemicals?

Contact urticaria due to gloves is mostly related to immediate-type allergy to natural rubber latex (NRL), and rarely due to rubber chemicals. We report the results of prick tests with rubber chemicals carried out on 75 latex-allergic patients. Clinically relevant hypersensitivity was not observed in our patient collection. Thus, we conclude that contact urticaria due to rubber chemicals is a very rare finding in latex-allergic patients, but has to be considered in patients with contact urticaria due to synthetic rubber gloves, as well as in patients with contact urticaria due to NRL gloves but no latex allergy. Therefore prick tests with rubber chemicals are unnecessary in the routine diagnostic assessment of latex-allergic patients.

Adolescent↗

Workplace risk factors for cancer in the German rubber industry: Part 1. Mortality from respiratory cancers.

OBJECTIVES: To determine the cancer specific mortality by work area among active and retired male workers in the German rubber industry. METHODS: A cohort of 11,663 male German workers was followed up for mortality from 1 January 1981 to 31 December 1991. Cohort members were classified as active (n = 7536) or retired (n = 4127) as of 1 January 1981 and had been employed for at least one year in one of five study plants producing tyres or technical rubber goods. Work histories were reconstructed with routinely documented "cost centre codes" which were classified into six categories: I preparation of materials; II production of technical rubber goods; III production of tyres; IV storage and dispatch; V maintenance; and VI others. Standardised mortality ratios (SMRs) adjusted for age and calendar year and 95% confidence intervals (95% CIs), stratified by work area (employment in respective work area for at least one year) and time related variables (year of hire, lagged years of employment in work area), were calculated from national reference rates. RESULTS: SMRs for laryngeal cancer were highest in work area I (SMR 253; 95% CI 93 to 551) and were significant among workers who were employed for > 10 years in this work area (SMR 330; 95% CI 107 to 779). Increased mortality rates from lung cancer were identified in work areas I (SMR 162; 95% CI 129 to 202), II (SMR 134; 95% CI 109 to 163), and V (SMR 131; 95% CI 102 to 167). Mortality from pleural cancer was increased in all six work areas, and significant excesses were found in work areas I (SMR 448; 95% CI 122 to 1146), II (SMR 505; 95% CI 202 to 1040), and V (SMR 554; 95% CI 179 to 1290). CONCLUSION: A causal relation between the excess of pleural cancer and exposure to asbestos among rubber workers is plausible and likely. In this study, the pattern of excess of lung cancer parallels the pattern of excess of pleural cancer. This points to asbestos as one risk factor for the excess deaths from lung cancer among rubber workers. The study provides further evidence for an increased mortality from laryngeal cancer among workers in the rubber industry, particularly in work area I.

Adult↗

Identification of mutagen exposures in the rubber industry by the sister chromatid exchange method.

The rubber industry is known to use a large and expanding array of chemicals, some of which are experimentally proven mutagens or carcinogens. An association with cancer risk has been shown in several epidemiological studies carried out in the rubber industry. Sister chromatid exchanges were studied in blood lymphocytes of 54 workers from various job categories in two rubber plants and 34 control subjects mainly from office jobs. The highest numbers of SCEs were observed among rubber workers who smoked, but smokers in the control group also differed significantly from non-smokers by their incidence of SCEs. In both rubber plants the highest incidence of SCEs was observed among workers employed in the mixing operations of the rubber chemicals.

Adult↗

Significance of rubber elongation factor as a latex allergen.

IgE-mediated hypersensitivity to proteins eluting from surgical gloves and other natural rubber products is a well-recognized allergic condition with special impact to health care workers and sensitized patients. Since rubber elongation factor (REF) has been suggested to be the major latex allergen (Hev b 1) we purified REF from rubber particles using electrophoresis and electroelution and reevaluated the occurrence of IgE antibodies to purified REF. The purified protein was subjected to tryptic digestion, peptide separation and amino acid sequencing. Amino acid sequences of 9 tryptic peptides from the purified 14-kD protein gave 100% homology to REF. In immunoblotting, sera from 4 of 6 latex-allergic children with spina bifida or other congenital anomalies exhibited IgE antibodies against REF whereas only 1 serum from the 30 other latex-allergic patients had similar antibodies. In IgE ELISA 8/45 (18%) latex-allergic patients had IgE antibodies to purified REF, whereas 30 (67%) of the same patients had IgE antibodies to purified prohevein, another rubber protein, recently shown to be a major natural rubber latex allergen. The observed overall low frequency of IgE antibodies to purified REF, as measured by two specific IgE assays, indicates that REF is one but not the most significant allergen among the natural rubber latex proteins.

Adolescent↗

Adding crumb rubber into exterior wall materials.

In Arizona US, most houses are built with walls covered by stuccos/coatings/mortars. This paper presents an explorative investigation of adding crumb rubber into stuccos/coatings/mortars. A series of experiments are conducted to examine the thermal and mechanical performance of the crumb rubber mixes. The results show that, the mixes with crumb rubber do exhibit more desirable performances like being high in crack-resistance and thermal insulation, and low in thermal expansion/contraction. The drawback for the crumb rubber mixes is the reduction in compressive strength, but which can be compensated by other means. As a site experiment, an area of 100 square-feet of crumb rubber coatings for two mix designs is sprayed on a tire-adobe wall. After being sprayed more than 14 months, the coatings apparently are in good condition. Significance of this study is that this practice, if accepted, will yield improved products that consume large quantities of crumb rubber.

Arizona↗

The efficacy of the rubber dam as a barrier to the spread of microorganisms during dental treatment.

This study evaluated the rubber dam as an infection control barrier during standard restorative procedures. Microbial collection was performed during preparation and placement of amalgam and composite resin restorations with and without the rubber dam, and during handpiece and air-water syringe spraying with and without the rubber dam. The results showed a significant reduction in microorganisms with the use of the rubber dam--70% to 88% and 95% to 99%, respectively; and 90% to 98% when all data were combined. These results indicate that using the rubber dam is a method of reducing microbial contamination at the primary source. Used with gloves, mask, and protective eyewear, the rubber dam provides an excellent barrier to the potential spread of infectious disease in the dental office.

Bacteria↗

Overview of the rubber industry and tire manufacturing.

The production of rubber and rubber products is a large and diverse industry. Natural rubber, obtained from plantations in Africa and Asia, accounts for only about 25% of the rubber used in industry. Synthetic alternatives, developed during World War II, are the primary sources of raw materials today. Health hazards in synthetic rubber production are primary related to exposure to monomers. An excess incidence of leukemia has been observed in styrene/butadiene rubber production, attributed to exposure to 1,3-butadiene. Excesses of cancer and respiratory disease have been reported, although specific causative agents are rarely identified. Exposures have varied greatly over the years, based on changes in materials used, work practices, and ventilation. In modern industry, exposures to noise, skin and respiratory irritants, and ergonomic stressors remain important. The tire industry, in particular, has been studied extensively over the past 50 years.

Automobiles↗

Economic status and occupational correlates of stomach cancer in the rubber industry.

Associations between stomach cancer and occupational exposure to rubber remain uncertain, and thus far only a few studies have been carried out to investigate risks of stomach cancer in different jobs in the rubber industry, and confounding of the risk/exposure relationship by non-occupational risk factors, especially by the economic status. This study was aimed to explore these questions. Following a case-cohort design, we used the data of 36 stomach cancer deaths in 1973-95 and a random sample (sub-cohort) of 188 from among 1598 subjects employed in a rubber plant in Shanghai, China. We analysed stomach cancer risks by the economic status, smoking, alcohol consumption, and residential exposure to coal burning-related pollution, etc., and assessed by jobs and years, unadjusted and adjusted. The rate ratios for stomach cancer were found to be 1.70 for 1-19 yr of employment and 1.79 for 20 or more yr of employment in the inner tire tube department. After the economic status was adjusted, the rate ratios were 1.54 and 1.64, respectively. Although the front processing of rubber was also included in our analysis no evidence of any excess risk of stomach cancer was found. Rate ratios adjusted for four job groups were the highest in the low income group. The association followed a pattern of a dose-response relationship--increasing rate ratios correlated with decreasing annual income (statistic trend: chi 2(1) = 8.35, p = 0.004). The data obtained suggest that excess risks of stomach cancer in the rubber workers were mainly related to their economic status and only slightly (some 1.6) to the talc powder exposure. Results of this study fail to provide any statistically significant evidence to support the hypothesis that there was high risk of death from stomach cancer among the rubber workers employed in high dusty departments.

China↗

[Potential neurosurgical damage of rubber bullets. Analysis of 2 pediatric cases].

We present 2 cases of craniocerebral injuries in children caused by rubber bullets. The potential severity of these projectiles is discussed. The first case was an eleven-year-old boy who died a few days after having been injured by a rubber bullet during a riot. He presented with a bi-hemispheric fronto-parietal craniocerebral injury with massive intraventricular hemorrhage. The second case was a fourteen-year-old boy also injured by a similar rubber bullet with an important left fronto-temporal cerebral contusion. These projectiles were composed of a metal cylinder (length: 1.7 cm, diameter: 1.7 cm) covered by a 2 mm layer of rubber. The term "rubber bullet" could give the impression that these projectiles are harmless. But, based on these observations and on the literature, these rubber bullets (like their predecessors) can induce severe, or even fatal craniocerebral injuries.

Adolescent↗