BACKGROUND: Airborne transmission of SARS-CoV-2 is an important route of infection. For the wildtype (WT) only a small proportion of those infected emitted large quantities of the virus. The currently prevalent variants of concern, Delta (B1.617.2) and Omicron (B.1.1.529), are characterized by higher viral loads and a lower minimal infective dose compared to the WT. We aimed to describe the resulting distribution of airborne viral emissions and to reassess the risk estimates for public settings given the higher viral load and infectivity. METHOD: We reran the Monte Carlo modelling to estimate viral emissions in the fine aerosol size range using available viral load data. We also updated our tool to simulate indoor airborne transmission of SARS-CoV-2 by including a CO2 calculator and recirculating air cleaning devices. We also assessed the consequences of the lower critical dose on the infection risk in public settings with different protection strategies. RESULTS: Our modelling suggests that a much larger proportion of individuals infected with the new variants are high, very high or super-emitters of airborne viruses: for the WT, one in 1,000 infected was a super-emitter; for Delta one in 30; and for Omicron one in 20 or one in 10, depending on the viral load estimate used. Testing of the effectiveness of protective strategies in view of the lower critical dose suggests that surgical masks are no longer sufficient in most public settings, while correctly fitted FFP2 respirators still provide sufficient protection, except in high aerosol producing situations such as singing or shouting. DISCUSSION: From an aerosol transmission perspective, the shift towards a larger proportion of very high emitting individuals, together with the strongly reduced critical dose, seem to be two important drivers of the aerosol risk, and are likely contributing to the observed rapid spread of the Delta and Omicron variants of concern. Reducing contacts, always wearing well-fitted FFP2 respirators when indoors, using ventilation and other methods to reduce airborne virus concentrations, and avoiding situations with loud voices seem critical to limiting these latest waves of the COVID-19 pandemic.

This study describes the use of pesticides mixtures and their potential association with comet assay results in 223 rice field workers in Colombia. Thirty-one pesticides were quantified in blood, serum, and urine (15 organochlorines, 10 organophosphorus, 5 carbamates, and ethylenethiourea), and the comet assay was performed. Twenty-four (77.42%) pesticides were present in the workers. The use of the maximum-likelihood factor analysis identified 8 different mixtures. Afterwards, robust regressions were used to explore associations between the factors identified and the comet assay. Two groups of mixtures— α-benzene hexachloride (α-BHC), hexachlorobenzene (HCB), and β-BHC (β: 1.21, 95% confidence interval [CI]: 0.33–2.10) and pirimiphos-methyl, malathion, bromophos-methyl, and bromophos-ethyl (β: 11.97, 95% CI: 2.34–21.60)—were associated with a higher percentage of DNA damage and comet tail length, respectively. The findings suggest that exposure to pesticides varies greatly among rice field workers.

Objetivo Caracterizar la forma en que los agricultores se exponen a los plaguicidas y se presenta la intoxicación.Materiales y Métodos Estudio multi-métodos multinivel (individuo y comunidad), que incluyó métodos etnográficos, encuesta y medición de plaguicidas en agua y muestras humanas.Resultados Se describió el proceso productivo y se conocieron los principales factores de riesgo. Los plaguicidas son considerados el mayor peligro en el trabajo y en sus viviendas. Los trabajadores tienen precarias condiciones laborales y no están protegidos por el sistema de riesgos laborales. En las muestras de agua se encontraron azinfos-metil, endosulfán, b-BHC, bromofos-metil, bromofos-etil y 2,4-DDT. En la encuesta participaron 381 trabajadores de los cuales 12.86, 67.98 y 5.51 % tuvieron intoxicaciones leves, moderadas y severas, respectivamente. Los casos severos tenían menores niveles de escolaridad, menor nivel de afiliación al régimen contributivo del sistema de seguridad social y un mayor número tenía enfermedad cardiovascular, diabetes, herpes u otras infecciones virales.Conclusión Existen precarias condiciones laborales que favorecen la exposición a plaguicidas caracterizadas por la exclusión del sistema de riesgos laborales, pobreza y baja educación. Es urgente la inclusión de estos trabajadores al sistema de riesgos laborales y la mejora de las condiciones de vida. De esa manera se podrán disminuir las prácticas inseguras en el manejo de plaguicidas.

OBJECTIVES: To determine the prevalence and nature of occupational injuries among children working in the streets of four major cities in Latin America, as well as to identify factors that predict these work-related injuries. METHODS: This cross-sectional study interviewed 584 children from 5-17 years of age working on the streets of Bogotá, Colombia; Lima, Peru; Quito, Ecuador; and São Paulo, Brazil. Descriptive analyses and multivariate logistic regressions were conducted, with incidence and serious injuries regressed on occupational and sociodemographic variables. RESULTS: Approximately 39.6% of the child street-laborers surveyed reported an injury sustained while working in the streets: scratches (19.5%), cuts/lacerations (16.4%), burns (8.6%), car accidents (8.9%), sprains (4.6%), and amputations (0.3%). Working a high number of daytime hours and performing on the street predicted the greatest risk of injury, even after controlling for sociodemographic factors; specifically, each additional hour of daytime work increased the risk of injury by 1.4%. Child performers had three times the injury rate of children primarily selling products. Boys, older children, and children in Quito were more likely to experience moderate-to-severe injuries, than girls, younger children, and street children in the other study cities. CONCLUSIONS: Interventions are needed to address the substantial risk of injury experienced by children working on the city streets of Latin America.