Documents cumulative properties 3 results

"Occupational exposure limits have traditionally focused on preventing morbidity and mortality arising from inhalation exposures to individual chemical stressors in the workplace. While central to occupational risk assessment, occupational exposure limits have limited application as a refined disease prevention tool because they do not account for all of the complexities of the work and non-occupational environments and are based on varying health endpoints. To be of greater utility, occupational exposure limits and other risk management tools could integrate broader consideration of risks from multiple exposure pathways and routes (aggregate risk) as well as the combined risk from exposure to both chemical and non-chemical stressors, within and beyond the workplace, including the possibility that such exposures may cause interactions or modify the toxic effects observed (cumulative risk). Although still at a rudimentary stage in many cases, a variety of methods and tools have been developed or are being used in allied risk assessment fields to incorporate such considerations in the risk assessment process. These approaches, which are collectively referred to as cumulative risk assessment, have potential to be adapted or modified for occupational scenarios and provide a tangible path forward for occupational risk assessment. Accounting for complex exposures in the workplace and the broader risks faced by the individual also requires a more complete consideration of the composite effects of occupational and non-occupational risk factors to fully assess and manage worker health problems. Barriers to integrating these different factors remain, but new and ongoing community-based and worker health-related initiatives may provide mechanisms for identifying and integrating risk from aggregate exposures and cumulative risks from all relevant sources, be they occupational or non-occupational."

"Inorganic nanoparticles are frequently engineered with an organic surface coating to improve their physicochemical properties, and it is well known that their colloidal properties1 may change upon internalization by cells. While the stability of such nanoparticles is typically assayed in simple in vitro tests, their stability in a mammalian organism remains unknown. Here, we show that firmly grafted polymer shells around gold nanoparticles may degrade when injected into rats. We synthesized monodisperse radioactively labelled gold nanoparticles (198Au) and engineered an111In-labelled polymer shell around them. Upon intravenous injection into rats, quantitative biodistribution analyses performed independently for 198Au and 111In showed partial removal of the polymer shell in vivo. While 198Au accumulates mostly in the liver, part of the 111In shows a non-particulate biodistribution similar to intravenous injection of chelated 111In. Further in vitrostudies suggest that degradation of the polymer shell is caused by proteolytic enzymes in the liver. Our results show that even nanoparticles with high colloidal stability can change their physicochemical properties in vivo."

Existing tools for monitoring work related neck and upper limb disorders were reviewed. Analysis indicated that there were 12 domains which were major areas of life affected when a worker suffers a neck or upper limb disorder. These 12 domains included work, household and family activities and responsibilities, care of one's self, driving and transportation functions, sexual activity, securing adequate restful sleep, participating in social activities, enjoying recreational hobbies, one's attitude and mood swings, one's own feeling of self importance and independence, monetary aspects due to lower wages or added expenses, and iatrogenic effects of assessments and treatment. The study examined 52 instruments which were identified as being able to determine the functional status of the patient. Of the 52 identified, 21 met criteria of dealing with items of work, self care and domestic responsibilities which indicated they had the potential to be relevant. These 21 were rated on a three point scale for relevance and comprehensiveness for each of the 12 domains. Of the 21 instruments tested, ten adequately covered the areas of work, self care and domestic responsibilities. Six covered these three areas and also recreational activities. Very few of the instruments examined dealt with sleep, self esteem, sexual activities, iatrogenic effects, or financial impact. The authors urge the development of a new instrument designed for this population of workers.