Explain the significance of the $$typical exposure level$$ reported in the study. Woodworking Monthly trade magazine: Working at the $$Wood Face$$Hardware stores, Do$-$It$-$Yourself $($DIY$)$ shops, and timber merchants often provide a wood$-$cutting service for their customers. These wood$-$cutting services are very popular and often drive increased sales of a wide range of timber. Customers are able to walk out of the store with the wood they need for a job already cut to size, reducing the time and effort they have to expend to complete a job in the workplace or at home.A vertical panel saw $($VPS$)$ is the tool of choice for those businesses offering this service as it gives a good degree of flexibility in the types of wood $($hard and soft$)$ and size that can be cut. There are however concerns about the health issues being experienced by some workers who operate this type of equipment especially as hardwood dust is classed as a carcinogen.Recently this national hardware store decided to take a closer look at the likely exposure to wood dust being experienced by the workers and commissioned an occupational hygienist to help determine this. The data from the study indicated that the typical exposure level of workers in the wood$-$cutting services was $4\mathrm{.}1$ mg$/$m$3(8-$hour time$-$weighted average $($TWA$)).$In addition to this exposure data, the study measured the particle size range of the wood dust being generated during the wood$-$cutting activities.This is shown in the table below:Particle size $($microns$)-$ below $0\mathrm{.}1($respirable$),\%$ by weight $9,$ Cumulative $\%$ by weight $9.$Particle size $($microns$)-0\mathrm{.}12\mathrm{.}5($respirable$),\%$ by weight $22,$ Cumulative $\%$ by weight $31.$Particle size $($microns$)2\mathrm{.}510($respirable$),\%$ by weight $23,$ Cumulative $\%$ by weight $54.$Particle size $($microns$)$ more than $10,\%$ by weight $46,$ Cumulative $\%$ by weight $100.$Research indicates which of these particles are respirable.The study was a warning for this hardware store chain especially when viewed alongside the occupational exposure limits for wood dust that are assigned in law.Workplace exposure limit:For substance: Hardwood dust $($inhalable fraction$)$:Long$-$term exposure limit $(8-$hr TWA reference period$)3$ mg$/$m$^3,$ short$-$term exposure limit $(15-$minute reference period$)-$Comments: Carc, Sen If hardwood dusts are mixed with other wood dusts, the WEL shall apply to all the wood dusts present in that mixture.For substance: Softwood dust:Long$-$term exposure limit $(8-$hr TWA reference period$)5$ mg$/$m$^3,$ short$-$term exposure limit $(15-$minute reference period$)$

Note: Your answer should be based on supporting document $2$ only.