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Simple Summary: Essential oils (EOs) from plants are promising products for pest management. This paper describes the chemical composition and repellent action of four EOs against Ulomoides dermestoides, a common pest on several stored products. Most abundant chemical components found in the EOs were sabinene, trans-β-caryophyllene, and α-humulene for phellandrene-rich Lippia origanoides; limonene and carvone for carvone-rich Lippia alba; geranial, geraniol, and neral for citral-rich Lippia alba; and α-guaiene, α-bulnesene, and patchoulol for Pogostemon cablin. The repellent bioactivity, carried out utilizing the area preference method, showed that all EOs displayed great repellency with low mortality rates, suggesting these natural mixtures can be used in formulations of repellents against stored grain pests. The essential oils (EOs) from bioactive species can provide an alternative tool for the management of stored grain insects that is less environmentally damaging than synthetic chemicals. The aim of this study was to assess the repellent action and toxicity of EOs obtained from phellandrene-rich Lippia origanoides, carvone-rich Lippia alba, citral-rich L. alba, and Pogostemon cablin aerial parts on adults of Ulomoides dermestoides. These EOs were isolated by hydrodistillation and characterized by gas chromatography coupled to mass spectrometry (GC-MS). The repellency assay was carried out using the area preference method, and the toxicity evaluated utilizing a filter paper contact test. The major components (>10%) of the studied EOs were sabinene (16.9%), trans-β-caryophyllene (18.6%) and α-humulene (10.1%) for phellandrene-rich L. origanoides EO; limonene (40.1%) and carvone (37.7%) for carvone-rich L. alba EO; geranial (24.5%), geraniol (19.0%), and neral (11.9%) for citral-rich L. alba EO; and α-guaiene (13.3%), α-bulnesene (15.7%), and patchoulol (35.3%) for P. cablin EO. All EOs displayed 100% repellency at a concentration of 16 μL/mL, with lower toxicity than that elicited by the commercial repellent DEET. EO concentrations up to 8 µL/mL did not induce any mortality on the beetle. These findings show that the EOs provide active and safe molecules for natural repellent formulations to prevent and control insect infestations of stored products. [ABSTRACT FROM AUTHOR]

Exposure to chemicals and particles generated in automotive repair shops is a common and underestimated problem. The objective of this study was to assess the genotoxic status of auto repair workers with (1) a questionnaire to gather sociodemographic information and self-reported exposure to hazardous chemicals and (2) measurement of various biochemical parameters. Blood and oral mucosa samples were collected from 174 male volunteers from Barranquilla, Colombia, aged 18–55 years: 87 were active car repairmen and 87 were individuals with no known exposure to hazardous chemicals. Peripheral blood lymphocytes were collected for the comet and cytokinesis-blocking micronucleus (CBMN) assays, while oral mucosal epithelium extracted to quantify micronucleated cells (MNC). DNA was extracted to assess polymorphisms in the DNA repair (XRCC1) and metabolism-related genes (GSTT1 and GSTM1) using PCR-RFLP. DNA damage and frequency of micronuclei (MN) in lymphocytes and oral mucosa were significantly higher in exposed compared to control group. In both groups genotypes and allelic variants for XRCC1 and GSTT1 met the Hardy-Weinberg equilibrium (HWE). In contrast, GSTM1 deviated from HWE. In the exposed group genotypic variants were not correlated with DNA damage or MN presence in cells. DNA damage and occurrence of MN in mucosa and lymphocytes correlated with age and time of service (occupational exposure ≥ 3 years). In summary, workers in car repair shops exhibited genotoxic effects depending upon exposure duration in the workplace which occurred independent of DNA repair XRCC1 gene and metabolism genes GSTT1 and GSTM1. Date demonstrate that health authorities improve air quality in auto repair facilities to avoid occupational DNA damage. [ABSTRACT FROM AUTHOR]

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Essential oils (EOs) represent valuable alternatives in handling pest insects in stored grains. The main objective of this study was to evaluate the chemical composition as well as the repellent, fumigant, and oviposition inhibition activities of the rosemary (Rosmarinus officinalis) and citronella (Cymbopogon nardus) EOs against Ulomoides dermestoides. Ethyl 3-[acetyl(butyl)amino] propanoate (IR3535), an active ingredient in repellent formulations was used as a positive control. The chemical compositions of the EOs were characterized by GC/MS. The EOs major compounds (>10 %) included 1,8-cineole (24.6 %), α-pinene (17.7 %), camphor (12.4 %), and camphene (11.3 %) for rosemary, whereas for citronella, the most abundant components were citronellal (25.3 %), citronellol (17.9 %) and geraniol (11.6 %). The biological action observed was dependent on the concentration used. Both EOs showed 100 %-repellency at the highest tested concentration (16 μL/mL) with RC50 values lower than 2.6 μL/mL after 4 h-exposure. Contact toxicity results showed that all treatments had mortality rates lower than 40 %, while fumigant action did not exceed 25 %. The exposure of adult insects to sublethal concentrations of the two EOs significantly inhibited oviposition at 2 and 4 μL/mL. These data suggest that citronella and rosemary EOs, employing different toxicity mechanisms, could be useful candidates for formulations utilized in the management and pest control in stored products. [ABSTRACT FROM AUTHOR]