Low-Cost, Distributed Environmental Monitors for Factory Worker Health

Abstract

An integrated network of environmental monitors was developed to continuously measure several airborne hazards in a manufacturing facility. The monitors integrated low-cost sensors to measure particulate matter, carbon monoxide, ozone and nitrogen dioxide, noise, temperature and humidity. The monitors were developed and tested in situ for three months in several overlapping deployments, before a full cohort of 40 was deployed in a heavy vehicle manufacturing facility for a year of data collection. The monitors collect data from each sensor and report them to a central database every 5 min. The work includes an experimental validation of the particle, gas and noise monitors. The R2 for the particle sensor ranges between 0.98 and 0.99 for particle mass densities up to 300 μg/m3. The R2 for the carbon monoxide sensor is 0.99 for concentrations up to 15 ppm. The R2 for the oxidizing gas sensor is 0.98 over the sensitive range from 20 to 180 ppb. The noise monitor is precise within 1% between 65 and 95 dBA. This work demonstrates the capability of distributed monitoring as a means to examine exposure variability in both space and time, building an important preliminary step towards a new approach for workplace hazard monitoring.

Sensor Selection to Improve Estimates of Particulate Matter Concentration from a Low-Cost Network

“…The microcomputer recorded measurements every 2 s and stored each sensor output locally and also broadcasted the data wirelessly to an on-site server. Validation of other sensors and description of the custom monitor are described in the literature; the gas sensors were evaluated by Afshar-Mohajer, et al [ 24 ], the noise sensor was designed and evaluated by Hallett, et al [ 25 ], and the custom monitors are described by Thomas, et al [ 26 ].…”

Evaluation of a 10 nm Particle Number Portable Emissions Measurement System (PEMS)

“…Different principles of operation were under discussion to be applied as particle number detectors [4]. The most commonly used PM sensors, such as those in ambient air monitoring [28,29], exposure assessment [30][31][32][33][34], vehicle cabin air quality [35], or even filter monitoring in diesel exhaust [36][37][38], were not applicable to vehicle exhaust due to their relatively large lower size, high detection limit, or slow response time. Currently, there are two concepts for the particle sensors (detectors) inside the on-board systems: condensation particle counters (CPCs), similar to those in laboratory systems, and advanced diffusion chargers (DCs) [4,39,40].…”

Estimating personal exposures from a multi-hazard sensor network

“…24 We have previously developed a multi-hazard sensor network constructed with low-cost sensors for PM, CO, oxidizing gases (O 3 + NO 2 ) and noise. 33 An industrial hygienist identified hazards at the study site, a heavy-vehicle manufacturing facility, and those of greatest occupational health importance were chosen for inclusion our sensor network. PM has well-characterized associations with cardiopulmonary and respiratory diseases, lung cancer, inflammation, oxidative stress, pulmonary infection, and lung function.…”