High exposure category
We classified in this category "the combination tasks",
which include patient room and bathroom cleaning tasks.
Due to the continuous application of many products one
after another, the potential for inhalation exposures can
be higher compared to when the tasks are performed separately.
The shadowed boxes in Figure 1 show tasks that
potentially generate higher airborne exposures. Because
these tasks are done in small volume environments, it is
possible that airborne VOC can increase rapidly in a short
period of time exposing the worker to inhalation risks.
The other group of tasks classified in this category
includes floor finishing tasks, such as stripping, waxing,
and buffing. The potential for inhalation exposures from
these tasks is higher compared to other tasks because: a)
the airborne exposure intensity is higher due to higher
VOC concentrations in the bulk product; b) they include
specific activities such as the use of stripping and buffing
machines, which can facilitate dust and particle re-suspension
in the air that can potentially be inhaled; and c) the
application of fans to speed up floor drying increases the
intensity of exposures to VOC. Quantitative exposure
assessment is necessary to evaluate the risk of particle
inhalation during floor finishing tasks. Although less frequent
overall, these tasks may contribute to high acute
exposure levels that can be related to irritation mechanisms
of asthma and other respiratory symptoms among
cleaning workers.
Dermal exposure potential
Two examples of step by step estimations of potential skin
exposures for mirror and floor cleaning are given in Additional
files 4 and 5. The results of DREAM estimates for
five cleaning tasks are presented in a graph given in Figure
2. This graph presents the total body potential skin exposure
for five tasks along with contribution of three exposure
routes emission, deposition and transfer for each
task. The results of individual body part contribution to
the potential total body dermal exposure/task for the five
cleaning task evaluated is presented in Figure 3.
According to the DREAM categories, cleaning tasks create
moderate (such as in floor cleaning tasks) and high potential
for dermal exposure (such as in mirror/window cleaning,
sink cleaning and toilet bowl cleaning tasks). We
identified the relative contribution of three dermal exposure
routes for different tasks as shown in Figure 2. As seen from this graph, the "emission" route contributes more to
the overall exposure compared to "transfer" and "deposition"
routes during mirror and toilet bowl cleaning. One
possible explanation to this finding is related to the spraying
activities that generate liquid particles with aerodynamic
diameter >100 μm that potentially reach the skin.
In the case of sink cleaning, the "emission" is lower
because the potential for aerosol particles to reach the
head and upper body parts here is lower compared to mirror
and toilet bowl spraying. Transfer contributed more
during floor cleaning, probably due to the continuous
hand contact with the mop handle contaminated with
cleaning solution. Overall, floor cleaning tasks were associated
with the lowest potential for dermal exposures.
Hands were identified as having the highest potential for
dermal exposure for most of the tasks. Forearms were at
the next highest risk of exposure during sink, toilet bowl
& mirror cleaning while for floor cleaning, feet and lower
legs were most prone to exposure.