Environmental Forensic Investigation of Fugitive Particulate Emissions from an Industrial Bulk Material Handling Facility
Air Dispersion Modeling, Environmental Sampling, Source Attribution, and Exposure Assessment
Project Overview
Industrial facilities that receive, store, transfer, and distribute dry bulk materials can generate fugitive particulate emissions capable of migrating beyond facility boundaries under certain operating and meteorological conditions. Evaluating these emissions requires a multidisciplinary environmental forensic investigation integrating atmospheric science, environmental chemistry, engineering, industrial hygiene, contaminant fate and transport, exposure assessment, and environmental modeling. Because fugitive particulate emissions are influenced by equipment design, operational practices, control technologies, meteorological conditions, and particle characteristics, determining whether off-site impacts have occurred requires the evaluation of multiple independent lines of scientific evidence rather than reliance on a single dataset (U.S. Environmental Protection Agency [EPA], 2024; American Meteorological Society & U.S. EPA, 2019).
RoseyFields conducted an environmental forensic investigation involving a large industrial bulk material handling operation where neighboring properties reported recurring particulate deposition and concerns regarding airborne dust migrating beyond the facility boundary. The primary objectives of the investigation were to identify potential emission sources, reconstruct historical particulate releases, evaluate atmospheric transport and deposition mechanisms, determine whether facility operations could account for observed environmental conditions, and assess potential human and environmental exposure pathways. The investigation was designed to evaluate the complete source-to-receptor relationship by integrating engineering evaluations, environmental sampling, air dispersion modeling, regulatory information, and environmental chemistry into a scientifically defensible assessment of fugitive particulate emissions.
The investigation incorporated review of operational records, engineering documentation, environmental sampling results, particulate characterization, meteorological data, regulatory information, and advanced atmospheric dispersion modeling using accepted scientific methodologies. Air dispersion modeling was integrated with soil, surface dust, and air sampling data to evaluate contaminant migration, deposition patterns, and potential off-site transport under representative operating conditions. By synthesizing multiple independent sources of evidence using a weight-of-evidence approach, the investigation reconstructed contaminant fate and transport, evaluated the effectiveness of emission controls, and assessed the relationship between facility operations and environmental conditions observed beyond the operational boundary. This multidisciplinary investigation illustrates how environmental forensic science can be applied to complex particulate emission investigations involving industrial operations, environmental exposure assessment, and source attribution (American Conference of Governmental Industrial Hygienists [ACGIH], 2024; U.S. Environmental Protection Agency [EPA], 2024).
Chemicals of Concern
The primary chemicals of concern evaluated during this environmental forensic investigation were airborne particulate matter generated during industrial bulk material handling operations, including total suspended particulate (TSP), inhalable particulate matter (PM₁₀), respirable particulate matter (PM₂.₅), and respirable crystalline silica. These materials are commonly associated with the handling, transfer, storage, and processing of mineral-based products and are of environmental and public health interest because they can become airborne, migrate beyond facility boundaries, deposit onto surrounding properties, and contribute to inhalation exposures under appropriate meteorological and operational conditions (U.S. Environmental Protection Agency [EPA], 2024; World Health Organization [WHO], 2021).
Particulate matter encompasses a broad range of particle sizes that behave differently once released into the atmosphere. Larger particles typically settle relatively close to their source through gravitational deposition, while finer particles remain suspended for longer periods and may be transported substantially greater distances by wind and atmospheric turbulence. Environmental fate and transport are influenced by particle diameter, density, surface characteristics, release height, meteorological conditions, and local terrain. Understanding these physical properties is essential when reconstructing historical emission events, evaluating off-site deposition, and performing source attribution analyses using air dispersion modeling (American Meteorological Society & U.S. EPA, 2019; Seinfeld & Pandis, 2016).
Respirable crystalline silica represents a particular environmental and occupational health concern because particles small enough to penetrate the gas-exchange region of the lungs have been associated with silicosis, chronic obstructive pulmonary disease, lung cancer, and other adverse respiratory outcomes following prolonged exposure. The International Agency for Research on Cancer classifies inhaled crystalline silica in occupational settings as a Group 1 human carcinogen, and numerous regulatory agencies have established exposure limits designed to reduce long-term health risks. Consequently, environmental forensic investigations involving mineral dust frequently evaluate both the overall particulate burden and the potential presence of respirable crystalline silica when assessing exposure pathways and human health implications (International Agency for Research on Cancer [IARC], 2012; National Institute for Occupational Safety and Health [NIOSH], 2002).
In addition to potential inhalation exposures, fugitive particulate emissions may result in the accumulation of dust on soil, vegetation, buildings, vehicles, and other outdoor surfaces. These deposition patterns provide valuable forensic evidence because they integrate contaminant transport over time and can be evaluated alongside environmental sampling, meteorological analyses, and atmospheric dispersion modeling to reconstruct historical emission patterns. The combined evaluation of airborne concentrations and surface deposition allows investigators to establish source-to-receptor relationships, distinguish local emissions from regional background conditions, and develop scientifically supported conclusions regarding contaminant migration and environmental impacts (U.S. Environmental Protection Agency [EPA], 2024; Holsen & Noll, 1992).
Methods
A multidisciplinary environmental forensic methodology was employed to evaluate whether fugitive particulate emissions generated during industrial bulk material handling operations contributed to off-site environmental impacts. The investigation integrated environmental engineering, atmospheric science, industrial hygiene, environmental chemistry, contaminant fate and transport, exposure assessment, and regulatory analysis to develop a scientifically supported understanding of particulate generation, atmospheric dispersion, deposition, and potential human exposure. Rather than relying on a single source of information, multiple independent datasets were evaluated using a weight-of-evidence approach to reconstruct historical emissions and assess their relationship to observed environmental conditions (U.S. Environmental Protection Agency [EPA], 2024; American Conference of Governmental Industrial Hygienists [ACGIH], 2024).
The investigation began with a comprehensive review of available engineering documentation, operational records, publicly available regulatory information, environmental permits, facility process descriptions, emissions inventories, historical aerial imagery, and environmental monitoring data. These materials were evaluated to identify potential emission sources, characterize material handling operations, document emission control technologies, and reconstruct historical operating conditions that could influence particulate generation and atmospheric release. Engineering evaluations also considered material transfer processes, storage practices, loading and unloading operations, and other activities commonly associated with fugitive particulate emissions from industrial bulk material handling facilities.
Environmental sampling data were reviewed to characterize particulate deposition on surrounding properties and evaluate whether observed dust accumulation was consistent with facility-derived emissions. Multiple environmental media were considered, including surface dust, soil, and air monitoring results where available. Laboratory analytical data were evaluated in conjunction with the physical characteristics of the sampled materials, allowing environmental observations to be compared with expected particulate composition associated with industrial mineral handling activities. The integration of environmental sampling with engineering information provided an important line of evidence supporting the evaluation of contaminant migration and source attribution (U.S. Environmental Protection Agency [EPA], 2008; ASTM International, 2021).
Atmospheric transport was evaluated using AERMOD, the U.S. Environmental Protection Agency’s preferred regulatory air dispersion model for near-field applications. The modeling incorporated representative emission source configurations, meteorological data, terrain characteristics, particle properties, and receptor locations to estimate airborne particulate concentrations and deposition patterns under a range of operating conditions. Source parameters were developed from available engineering information, emissions data, and facility operating characteristics, allowing the model to simulate both airborne transport and surface deposition of fugitive particulate emissions. Air dispersion modeling results were subsequently compared with environmental sampling observations to evaluate consistency between predicted contaminant migration and measured environmental conditions (U.S. Environmental Protection Agency [EPA], 2024; American Meteorological Society & U.S. EPA, 2019).
Meteorological conditions were evaluated because wind speed, wind direction, atmospheric stability, mixing height, and precipitation strongly influence the transport and deposition of airborne particulates. These factors were incorporated into the air dispersion modeling and environmental interpretation to assess how changing atmospheric conditions affected the movement of particulates beyond the facility boundary. Consideration of local meteorology allowed the investigation to distinguish short-term emission events from long-term deposition patterns and provided additional confidence in the reconstruction of contaminant fate and transport (Seinfeld & Pandis, 2016).
Finally, all engineering evaluations, environmental sampling data, air dispersion modeling results, meteorological analyses, and regulatory information were integrated using a weight-of-evidence framework. This multidisciplinary approach allowed independent lines of scientific evidence to be evaluated collectively rather than in isolation, providing a robust environmental forensic assessment of particulate emissions, source attribution, atmospheric transport, environmental deposition, and potential exposure pathways. Such integrated investigations are widely recognized as the most scientifically defensible approach for evaluating complex environmental contamination scenarios involving fugitive airborne particulates (National Research Council, 2009; EPA, 2024).
Results
The environmental forensic investigation demonstrated that multiple independent lines of scientific evidence were consistent with fugitive particulate emissions migrating beyond the operational boundary of the industrial facility. Engineering evaluations, environmental sampling, atmospheric dispersion modeling, and regulatory information collectively supported the conclusion that routine material-handling activities were capable of generating airborne particulates that dispersed downwind and deposited onto surrounding properties. Rather than relying on a single dataset, the investigation integrated complementary sources of evidence that independently supported the observed environmental distribution of particulate matter (U.S. Environmental Protection Agency [EPA], 2024; American Meteorological Society & U.S. EPA, 2019).
Air dispersion modeling indicated that particulate emissions generated during routine industrial operations could be transported beyond the facility under representative meteorological conditions. Predicted concentration and deposition patterns were consistent with expected atmospheric behavior of fugitive mineral dust, demonstrating that particle transport was influenced by source configuration, emission characteristics, wind direction, atmospheric stability, and particle size. The modeling further illustrated that airborne particulates were capable of affecting areas beyond the immediate operational footprint, with deposition occurring in locations consistent with prevailing transport pathways and established atmospheric dispersion principles (Seinfeld & Pandis, 2016; EPA, 2024).
Environmental sampling provided an independent line of evidence supporting the air dispersion analysis. Evaluation of surface dust, soil, and other environmental media demonstrated particulate accumulation patterns that were spatially consistent with modeled transport and deposition. The physical characteristics and distribution of the collected materials were compatible with emissions generated during industrial bulk material handling activities, providing additional support for the source attribution analysis. Considered collectively, the environmental sampling results and atmospheric modeling demonstrated a consistent relationship between facility operations and observed off-site particulate deposition (ASTM International, 2021; Holsen & Noll, 1992).
Review of engineering information and operational documentation identified multiple activities with the potential to generate fugitive particulate emissions during the handling, transfer, storage, and movement of dry bulk materials. The investigation determined that even under normal operating conditions, these processes can release airborne particulates unless effectively controlled through engineering design, enclosure systems, material handling practices, and emission control technologies. Evaluation of the available operational information further demonstrated the importance of considering actual facility operating conditions when assessing emission potential rather than relying solely on generalized assumptions or theoretical emission estimates (EPA, 2024).
The investigation also demonstrated the importance of integrating environmental forensic disciplines when evaluating complex particulate emission cases. Air dispersion modeling alone cannot establish source attribution without supporting environmental evidence, while environmental sampling alone may not fully explain contaminant transport or historical emission patterns. By combining engineering evaluations, atmospheric modeling, environmental chemistry, meteorological analysis, and environmental sampling using a weight-of-evidence framework, the investigation developed a scientifically supported reconstruction of particulate generation, atmospheric transport, environmental deposition, and potential exposure pathways. This multidisciplinary approach substantially increased confidence in the technical conclusions and provided a comprehensive environmental forensic assessment of the relationship between industrial operations and off-site particulate impacts (National Research Council, 2009; American Conference of Governmental Industrial Hygienists [ACGIH], 2024).
Conclusions
This environmental forensic investigation demonstrated the value of integrating multiple scientific disciplines to evaluate fugitive particulate emissions from industrial bulk material handling operations. Rather than relying on individual measurements or isolated observations, the investigation combined engineering analyses, environmental chemistry, atmospheric science, industrial hygiene, environmental sampling, air dispersion modeling, and exposure assessment to reconstruct particulate generation, atmospheric transport, environmental deposition, and potential human exposure. The resulting weight-of-evidence evaluation provided a comprehensive and scientifically defensible assessment of the relationship between industrial operations and off-site particulate impacts (U.S. Environmental Protection Agency [EPA], 2024; American Conference of Governmental Industrial Hygienists [ACGIH], 2024).
The investigation demonstrated that atmospheric dispersion modeling is a powerful environmental forensic tool when integrated with environmental sampling and engineering evaluations. Modeling results provided a scientifically supported reconstruction of particulate transport under representative operating and meteorological conditions, while environmental sampling independently evaluated whether predicted deposition patterns were consistent with observed field conditions. Together, these complementary approaches strengthened source attribution and improved confidence in the overall technical conclusions by demonstrating agreement among multiple independent lines of evidence (American Meteorological Society & U.S. EPA, 2019; Seinfeld & Pandis, 2016).
The investigation further illustrated that evaluating fugitive particulate emissions requires consideration of the complete source-to-receptor pathway, including emission generation, engineering controls, atmospheric transport, environmental deposition, and potential exposure pathways. Because particulate emissions are influenced by facility operations, meteorological conditions, particle characteristics, and emission control performance, comprehensive environmental forensic investigations must evaluate each of these factors collectively rather than independently. This multidisciplinary approach provides a more accurate understanding of environmental impacts than any single analytical technique alone and is consistent with accepted environmental engineering and exposure assessment practices (National Research Council, 2009; EPA, 2024).
Environmental forensic investigations of this nature play an increasingly important role in environmental consulting, regulatory investigations, environmental due diligence, and environmental litigation. By integrating advanced air dispersion modeling, environmental sampling, contaminant fate and transport analyses, exposure science, and engineering evaluations, RoseyFields provides scientifically rigorous assessments capable of addressing complex particulate emission scenarios while supporting technically sound decision-making. This multidisciplinary methodology provides clients, regulators, and legal professionals with objective, evidence-based evaluations of environmental conditions, source attribution, and potential human and environmental exposures consistent with current scientific standards and best professional practices (ASTM International, 2021; U.S. Environmental Protection Agency [EPA], 2024).
This investigation was conducted under the direction of Dr. Paul Rosenfeld, an environmental scientist and environmental forensic expert with extensive experience in fugitive dust investigations, particulate matter exposure assessment, air dispersion modeling, source attribution, environmental sampling, and human health risk evaluation. Dr. Rosenfeld’s work focuses on complex environmental contamination matters involving airborne particulate emissions, industrial bulk material handling operations, off-site dust migration, soil and surface dust deposition, contaminant fate and transport, and exposure assessment in residential, commercial, and industrial settings. His expertise includes the use of AERMOD and other technical methods to evaluate source-to-receptor relationships, reconstruct historical emission scenarios, assess the effectiveness of engineering and operational controls, and determine whether facility operations are consistent with observed environmental conditions. Through RoseyFields LLC, Dr. Rosenfeld provides environmental forensic analysis, regulatory and compliance support, toxic tort and personal injury case evaluation, environmental due diligence, and expert witness testimony involving particulate emissions, industrial air quality impacts, contaminant migration, and long-term human and environmental exposure concerns.
References
American Conference of Governmental Industrial Hygienists. (2024). TLVs® and BEIs®: Threshold limit values for chemical substances and physical agents and biological exposure indices. ACGIH.
American Meteorological Society & U.S. Environmental Protection Agency. (2019). AERMOD: Description of model formulation. U.S. Environmental Protection Agency.
ASTM International. (2021). Standard guide for environmental forensic investigations (ASTM E1527 and related environmental forensic guidance). ASTM International.
Holsen, T. M., & Noll, K. E. (1992). Dry deposition of atmospheric particles: Application of current models to ambient data. Environmental Science & Technology, 26(9), 1807–1815.
National Research Council. (2009). Science and decisions: Advancing risk assessment. National Academies Press.
Seinfeld, J. H., & Pandis, S. N. (2016). Atmospheric chemistry and physics: From air pollution to climate change (3rd ed.). John Wiley & Sons.
U.S. Environmental Protection Agency. (2008). AP-42: Compilation of air pollutant emission factors (5th ed.). U.S. Environmental Protection Agency.
U.S. Environmental Protection Agency. (2024). Guideline on air quality models (40 CFR Part 51, Appendix W). U.S. Environmental Protection Agency.
World Health Organization. (2021). WHO global air quality guidelines: Particulate matter (PM₂.₅ and PM₁₀), ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. World Health Organization.
———————————————————————————————————————————————