Cytogenetic analysis of buccal cells from shoeworkers and pathology and anatomy laboratory workers exposed to n-hexane,toluene, methyl ethyl ketone and formaldehyde

People employed in the shoe manufacture and repair industry are at an increased risk for cancer, the strongest evidence being for nasal cancer and leukaemia. A possible causal role for formaldehyde is likely for cancer of the buccal cavity and nasopharynx. Exfoliated buccal cells are good source of tissue for monitoring human exposure to inhaled and ingested occupational and environmental genotoxicants. To assess the cytogenetic damage related to occupational exposure to airborne chemicals during shoe-making and the processes in pathology and anatomy laboratories, the micronuclei (MN) count per 3000 cells was measured in buccal smears from shoe-workers (group I, n = 22) exposed to mainly n-hexane, toluene and methyl ethyl ketone (MEK) and from anatomy and pathology staff (group II, n = 28) exposed to formaldehyde (FA). Eighteen male university staff were used as controls. The mean time-weighted average (TWA) concentrations of n-hexane, toluene and MEK in 10 small shoe workshops were 58.07 p.p.m., 26.62 p.p.m. and 11.39 p.p.m., respectively. The measured air concentrations of FA in the breathing zone of the anatomy and pathology laboratory workers were between 2 and 4 p.p.m. Levels of 2,5-hexadione (2,5-HD) and hippuric acid (HA), metabolic markers of n-hexane and toluene exposure, respectively, were significantly higher in the urine of workers in group I than in control subjects (p < 0.001 and p < 0.01, respectively). The mean (±SD) MN frequencies in buccal mucosa cells from workers in group I, group II and controls were 0.62±0.45%, 0.71±0.56% and 0.33±0.30%, respectively (p < 0.05 and p < 0.05 compared with controls for group I and group II, respectively). The effects of smoking, age and duration of exposure on the frequency of micronucleated buccal cells from workers in all three groups studied were also evaluated. Overall, the results suggest that occupational exposure to organic solvents, mainly n-hexane, toluene, MEK and FA, may cause cytogenetic damage in buccal cells and that use of exfoliated buccal cells seems to be appropriate to measure exposure to organic solvents.     

Predictors of healthcare workers' intention to vaccinate against COVID-19: A cross sectional study from Saudi Arabia

BackgroundVaccination is considered the best way to prevent the spread of COVID-19 and to prevent the complications of the disease. Nevertheless, no awareness campaigns were conducted in Saudi Arabia until March 1, 2021, when the Vaxzevria, or ChAdOx1 nCoV-19 (AZD1222), vaccine became available.ObjectivesThis study aims to determine the factors that can predict healthcare workers’ acceptance of the COVID-19 vaccine.MethodsA cross-sectional study was conducted from July to September 2021, in our university tertiary hospital (King Saud University Medical City [KSUMC]), Riyadh, Saudi Arabia. The study targeted potential participants among healthcare workers at KSUMC. We assessed healthcare workers’ perceptions and beliefs about the COVID-19 vaccine via a questionnaire that was distributed via social media applications such as WhatsApp, Twitter, and Google. Participants were informed about the questionnaire before they filled it out, and they were asked to respond to three screening questions before beginning the main questionnaire. These screening questions ensured that the participants met the inclusion criteria. Included participants were over the age of 18, agreed to answer the questions, and were residents of Saudi Arabia. The participants filled out the self-administered questionnaire.ResultsA total of 529 participants completed the questionnaires. All participants were vaccinated, 68% were female, 55% were married, 35% had been working for less than five years, and 65% had a bachelor’s degree. More than half of participants had not previously been infected with COVID-19, and most did not interact with COVID-19 patients. More convenient access to the vaccine increased the odds ratio of participant vaccination by 0.39. An increase in the number of vaccinated friends and family members increased the odds ratio of participant vaccination by 0.30. However, COVID- 19 vaccination mandates decreased the odds ratio of participant vaccination by 0.27. The fitted linear regression model explained 32% of the variation observed in the dependent variable, acceptance of the COVID-19 vaccine, and the adjusted R squared was 0.32. The fitted regression model was statistically significant at a 95% confidence interval; the p-value was 0.00001.ConclusionIn Saudi Arabia, there is an immense need to increase uptake of the COVID-19 vaccine. This requires encouraging more positive beliefs and attitudes regarding vaccination in general and the COVID-19 vaccine in particular.     

The organization of honeybee ocelli: Regional specializations and rhabdom arrangements

We have re-investigated the organization of ocelli in honeybee workers and drones. Ocellar lenses are divided into a dorsal and a ventral part by a cusp-shaped indentation. The retina is also divided, with a ventral retina looking skywards and a dorsal retina looking at the horizon. The focal plane of lenses lies behind the retina in lateral ocelli, but within the dorsal retina in the median ocellus of both workers and drones. Ventral retinula cells are ca. 25 μm long with dense screening pigments. Dorsal retinula cells are ca. 60 μm long with sparse pigmentation mainly restricted to their proximal parts. Pairs of retinula cells form flat, non-twisting rhabdom sheets with elongated, straight, rectangular cross-sections, on average 8.7 μm long and 1 μm wide. Honeybee ocellar rhabdoms have shorter and straighter cross-sections than those recently described in the night-active bee Megalopta genalis. Across the retina, rhabdoms form a fan-shaped pattern of orientations. In each ocellus, ventral and dorsal retinula cell axons project into two separate neuropils, converging on few large neurons in the dorsal, and on many small neurons in the ventral neuropil. The divided nature of the ocelli, together with the particular construction and arrangement of rhabdoms, suggest that ocelli are not only involved in attitude control, but might also provide skylight polarization compass information.     

Primitive accumulation in modern China

This article surveys the history of primitive accumulation in China, from the early 1980s to the mid 2000s. It observes that the principal means of primitive accumulation have been the transformation of state and collective enterprises into capital, the peasants’ loss of land through various forms of dispossession, and the voluntary migration of peasants from agricultural to industrial pursuits. These mix dispossession and market mechanisms in complex ways. They have involved the creation of markets; but more, the creation of workers and capital. While the processes that drive primitive accumulation have economic logics, they also have logics that derive from concerns over social welfare, over environmental management, and over ethnic struggles. Furthermore, the state has been closely involved in the entire process—as a regionally differentiated actor, directly involved in ownership, asset transformation and the control of migration. Primitive accumulation in China does not have one motive, does not simply reflect class interests, is not a particular case of a global capitalist project, but is complex and localised.     

Examination of ras (P21) proteins in plasma from workers exposed to benzene emissions from petrochemical plants and healthy controls

Exposure of workers to benzene and polyaromatic hydrocarbons has been documented to be at relatively high levels in the production of benzene and in the coking process at a petrochemical plant in the oil shale area in Estonia. Altogether 97 plasma samples from workers and 40 from unexposed matched referents from two samplings in different seasons were analyzed for the presence of ras (P21) proteins; of the workers 50 were exposed to benzene in the benzene production plant and 47 to polyaromatic hydrocarbons and benzene in a cokery. Proteins were separated by gel electrophoresis, transferred to a nitrocellulose membrane by Western blotting and detected by chemiluminescence, using a monoclonal antibody as the primary antibody. There were no statistically significant differences between the exposed and the referent groups. The results are thus in keeping with the lack of exposure related cytogenetic effects for this same workforce.     

Determining colony densities in wild honeybee populations (<Emphasis Type="Italic">Apis mellifera</Emphasis>) with linked microsatellite DNA markers

Estimating the population size of social bee colonies in the wild is often difficult because nests are highly cryptic. Because of the honeybee (Apis mellifera) mating behaviour, which is characterized by multiple mating of queens at drone congregation areas (DCA), it is possible to use genotypes of drones caught at these areas to infer the number of colonies in a given region. However, DCAs are difficult to locate and we assess the effectiveness of an alternative sampling technique to determine colony density based on inferring male genotypes from queen offspring. We compare these methods in the same population of wild honeybees, Apis mellifera scutellata. A set of linked microsatellite loci is used to decrease the frequency of recombination among marker loci and therefore increase the precision of the estimates. Estimates of population size obtained through sampling of queen offspring is significantly larger than that obtained by sampling drones at DCAs. This difference may be due to the more extensive flying range of queens compared with drones on mating flights. We estimate that the population size sampled through queen offspring is about double that sampled through drones.     

Carcinogenicity of chrysotile asbestos: A case control study of textile workers

Chrysotile is the predominant type of asbestos used in the United States and thus represents the most important source of exposure to asbestos already in place. While the steepest exposure-response observed for lung cancer has been in workers exposed to chrysotile in textile operations, some argue that chrysotile is less carcinogenic than amphibole asbestos types. Mineral oil exposures have been hypothesized to be responsible for the highly elevated lung cancer risk seen in textile workers. A lung cancer case-control analysis among a cohort of South Carolina chrysotile asbestos textile workers was conducted. Only a modest reduction in the slope of the lung cancer exposure-response relationship was observed after controlling for mineral oil exposures. These data do not support mineral oil exposure as a plausible explanation for the elevated lung cancer risk seen in chrysotile asbestos textile workers. The possible role of longer, thinner, more carcinogenic fibers in textiles is one plausible hypothesis needing further investigation.     

Cytogenetic biomonitoring of workers from laboratories of clinical analyses occupationally exposed to chemicals

A cytogenetic monitoring study was carried out on a group of workers in clinical analysis laboratories to investigate the risk of occupational exposure to chronic low levels of chemicals.Thirty-four clinical laboratories have been involved in the study. In these laboratories, toxicants and analytical procedures utilized have been characterized. The individual occupational exposure of workers was assessed by use of a questionnaire concerning the chemical substances utilized. About 300 different chemicals have been identified.Cytogenetic analyses (chromosomal aberration and micronucleus tests) were carried out on a strictly selected group of 50 workers enrolled from these laboratories and compared to 53 controls (healthy blood donors) matched for gender and age.The exposed group shows a significantly higher frequency of genetic damage than the control group. Both chromatid and chromosome aberration frequencies in workers appear significantly higher than in controls. Similarly, comparison between micronucleated cells rates of exposed and unexposed groups show significantly higher frequencies of binucleated cells with micronucleus (BNMN) and of total micronuclei (MN tot) in workers than in controls.     

Evaluation of Non Ionizing Radiation Around the Dielectric Heaters and Sealers: A Case Report

Dielectric heaters and sealers present the most common source of occupational exposure to excessive radio frequency (RF) fields. These systems are used industrially to heat or melt dielectric materials. Nowadays, the effects of high frequency electromagnetic (EM) fields on the health have been discussed frequently but there are few health studies done for workers around dielectric heaters and sealers. In this study, the leakage fields around dielectric heaters and sealers (27.12?MHz) were measured in MKE – Mechanical and Chemical Industry Corporation, Gazi Rocket Factory and evaluated in terms of standards. It has been observed that operators exposed to same RF fields with occupational exposure limits. Many workers have health complaints, such as elevated body temperatures in the factory. Safe distances or areas for workers should be recommended in these systems. Protective measures could be implemented to minimize these exposures. Further measurements and occupational exposure studies of RF exposed women and men are needed to demonstrate the levels of exposed Radio Frequency Radiation (RFR). Precautions should therefore be taken either to reduce the leakage fields or minimise the exposed fields.