Occupational exposure to respirable dust (RD) and respirable crystalline silica (RCS) remains a significant health risk in mining environments, and direct-reading instruments (DRIs) for particulate matter (PM) have the potential to improve exposure assessment. The aim of this study was to evaluate personal RD exposure patterns during waste processing operations with side-by-side sampling following a standard gravimetric sampling protocol alongside DRIs. Bulk tailings dam material was analyzed for mineralogical composition and particle size using X-ray diffraction (XRD) and automated static imaging analysis, respectively. Forty paired side-by-side personal RD samples were collected at three gold mine waste processing operations (one tailings dam and two remining sites) using the gravimetric MDHS 14/4 method and DRIs (Nanozen DustCount 9000i or TSI SidePak AM520i). Additionally, filters from gravimetric sampling were analyzed for quartz by an external laboratory following the NIOSH 7500 analysis method. Bulk analysis of material revealed that samples contained 84 to 86% of quartz, and approximately 90% of the particles were in the respirable size fraction (<10 μm) and >10% were submicron in size. Gravimetric RD 8-h time-weighted average (8h-TWA) concentrations ranged from 0.044 to 0.585 mg/m3, while RCS 8h-TWA exposure concentrations ranged from <0.001 to 0.170 mg/m3, of which 5 samples exceeded the RCS occupational exposure limit (OEL) of 0.05 mg/m3. According to Bland–Altman analysis, the Nanozen DustCount 9000i and the TSI SidePak AM520i underestimated respirable dust 8h-TWA exposure concentrations compared with the gravimetric method (mean bias = −0.107 mg/m3 and −0.089 mg/m3, respectively). DRIs identified task-related and environment-related short-duration peak exposures not identified by gravimetric sampling. The DRIs underestimated RD mass concentrations compared to gravimetric methods but identified exposure patterns, making them a practical complementary tool in occupational hygiene monitoring programs.
Abstract Laboratories that use hazardous chemicals accumulate the physical conditions that precede fire, explosion, and toxic release. Safety audits record these accident precursors where they are observed, and the resulting counts are aggregated to evaluate the safety management of the unit in which they were found. That evaluative use assumes a finding recorded in a laboratory reflects the laboratory’s own management. This assumption fails when durable correction requires authority, funding, or technical competence held at a higher organizational level. We analyzed a regulator-commissioned third-party audit of 135 high-risk hazardous-chemical laboratories in 47 colleges across eight Chinese universities. A human-verified workflow decomposed 6152 audit records into 10,044 discrete findings, and experts classified each finding by type (safety management system deficiency versus accident precursor) and by corrective-action responsibility (independent recoding: Fleiss’ kappa = 0.984 and 0.949). Under the study’s corrective-action responsibility rule, 829 of 2346 recorded precursors (35.3%) were classified as requiring institutional maintenance or engineering action for durable correction, and every laboratory contained at least one. Under university fixed effects with college-clustered robust inference, each additional laboratory-level management deficiency was associated with 0.208 more laboratory-responsibility precursors (95% CI [0.100, 0.316]) but not with maintenance-responsibility precursors (0.025, 95% CI [−0.088, 0.138]); the difference (0.183, 95% CI [0.072, 0.294]) persisted after standardization. Audit findings therefore remain valid risk information wherever they are recorded, but their evidential value about the audited unit’s management ends at that unit’s corrective-action authority. Audits should retain location-based records for hazard control and escalation while attributing performance by authority for durable correction.
Abstract Psychosocial safety climate (PSC) and trust and comfort (TC) are proposed as key indicators of safe laboratory environments, yet their relationships with both safety behaviors and interpersonal mistreatment remain underexamined in academic chemical contexts. We surveyed NIH-supported trainees working in laboratories that reported following chemical safety protocols (N = 134) using a two-wave design to examine concurrent and prospective associations among PSC, TC, safety compliance, unsafe laboratory practices, and interpersonal mistreatment (HARM; sexual harassment, racial mistreatment, and incivility). PSC and TC were positively associated with safety compliance and negatively associated with unsafe practices and interpersonal mistreatment. Several relationships persisted over a 10 day interval, suggesting that psychosocial safety conditions are relevant to both technical and interpersonal dimensions of laboratory safety. Gender and racial/ethnic group comparisons were descriptive and did not reveal statistically significant differences. These findings support integrating psychosocial safety into laboratory safety frameworks such as Recognize, Assess, Minimize, Prepare (RAMP), using PSC and TC as assessment indicators that can identify social and organizational conditions relevant to minimizing laboratory safety risk.
Abstract Advanced physicochemical characterization relies on high-value analytical instrumentation, yet its broader lifecycle costs remain insufficiently examined. One approach to addressing this gap is to assess costs generated throughout the operational life of laboratory equipment. In this study, the suitability of Life Cycle Costing for evaluating the economic performance of scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and differential mobility spectrometry (DMS500) was assessed, using one operating hour as the functional unit. Under the base-case scenario, DMS500 exhibited the lowest lifecycle cost (€0.84 million), followed by ICP-MS (€0.99 million), whereas SEM presented the highest cost. When accident-related costs were incorporated, the lifecycle cost of SEM increased from €1.20 million to €1.34 million, corresponding to an increase of 11.7%. With accident costs incorporated, SEM exceeded ICP-MS and DMS500 by approximately €357,000 and €501,000, respectively. The analysis is based on data from one laboratory, applies a time-based functional unit that does not represent equivalent analytical output, and reflects the current availability of empirical accident-related information. A key feature of the proposed framework is the integration of lifecycle economic assessment with safety-related costs. The findings demonstrate that accident-related cost can substantially increase the SEM lifecycle cost without changing its comparative economic position. Future work should expand the economic profiling of analytical instrumentation and evaluate how avoided accident costs evolve over time. Expanding laboratory logbooks into structured tools for documenting associated costs could strengthen the evidence base for accident costs and support more informed lifecycle economic decision-making.
Abstract With the glorious progress and applications in the field of unmanned aerial vehicles and low-altitude economy, the safe use of lithium-ion batteries in daily life has become indispensable and pivotal. It is unfortunate that there has not been any evaluation of the risk of LIBs being exposed to thermal abuse in unmanned aerial vehicles. The topic of thermal runaway of LIB used in unmanned aerial vehicles is not well-studied. Three different brands of LIBs (including Fullymax, ACE, and SEFU ones) were studied using pseudoadiabatic calorimeter. Runaway data of exothermic onset temperature (Tonset), crucial temperature (Tcr), maximum temperature (Tmax), maximum self-heat rate ((dT/dt)max), maximum pressure (Pmax) and amount of noncondensable gases (Δn) were determined among these LIBs under 25%, 50% and 100% SOCs. Thermal stability (higher Tonset), no return hazard (lower Tcr), fire hazard (higher Tmax), rate hazard (higher (dT/dt)max), and pressure hazard (higher Pmax or higher Δn) are among the thermal risk classifications. The discussion covers thermal risk that include stability, no return hazard, fire hazard, rate hazard, and pressure hazard. SEFU battery is the most unstable (with a lowest Tonset of 90.0 °C) among these three LIBs; however, the ACE is relatively stable due to its higher Tonset of 105.1 °C. Even though they have similar Pmax, the Fullymax one can be deduced to be the most dangerous with the highest Tmax (related to fire hazard) of 605.3 °C and largest (dT/dt)max (related to rate hazard) of 6720 °C min–1. All these three LIBs used in UAV possess potential risk because of their possible fire hazard (Tmax > AIT of carbonate), rate hazard ((dT/dt)max > 2730 °C min–1) and pressure hazard (Pmax> 18.1 bar) under unexpected abuses in flying tasks. Identified from the aforementioned runaway parameters, thermal risk can be generally ranked as thermal stability: ACE > Fullymax > SEFU; no return hazard: ACE > SEFU > Fullymax; fire hazard: Fullymax > ACE > SEFU; rate hazard: Fullymax > SEFU > ACE; pressure hazard: SEFU > ACE > Fullymax.
