Timothy R. Kelley

A Brief Review of Silicosis in the United States

Silicosis may be defined as the disease resulting from chronic occupational exposure to silica dust. Silica is primarily composed of quartz dust and has been classified since 2000 as a known human carcinogen by the U.S. government. Silicosis may lead to impairment of lung function resulting from fibrosis of the lungs. This may in turn lead to an increased susceptibility to the development of tuberculosis. Respirable particles are in the size range of less than one micrometer to as large as 30 micrometers. Silicosis is an untreatable, but preventable disease. This review explores the history of silicosis in the U.S. mining industry, including case studies of occupational silicosis.

Solids, organic load and nutrient concentration reductions in swine waste slurry using a polyacrylamide (PAM)-aided solids flocculation treatment

Increased swine production results in concentration of wastes generated within a limited geographical area, which may lead to land application rates exceeding the local or regional assimilatory capacity. This may result in pollutant transfer through surface water or soil-groundwater systems, environmental degradation, and/or odor concerns. Existing swine waste pit storage and lagoon treatment technologies may be inadequate to store or treat waste prior to land application without these concerns resulting. Efficient swine waste solids separation may reduce environmental health concerns and generate a value-added bioresource (solids). This study evaluated the efficiency of a polyacrylamide (PAM) flocculant-aided solids separation treatment to reduce pollution indicator concentrations in raw (untreated) swine waste slurry. Swine waste slurry solids separation efficiency through gravity settling (sedimentation) was evaluated before and after the addition of a proprietary polymeric (PAM) flocculant. Results indicated that polymer amendments at concentrations of 62.5-750 mg/l improved slurry solids separation efficiency and significantly reduced concentrations of other associated aquatic pollution indicators in a majority of analyses conducted (33 of 50 total analyses conducted). Results also suggested that PAM-aided solids separation from swine waste slurry might facilitate further treatment and/or disposal and therefore reduce associated environmental degradation potential.

Characterization of microbial communities in a pilot-scale constructed wetland using PLFA and PCR-DGGE analyses.

Phospholipid fatty acid (PLFA) analysis and 16S ribosomal DNA polymerase chain reaction amplification-denaturing gradient gel electrophoresis (PCR-DGGE) were used to determine microbial communities and predominant microbial populations in water samples collected from a pilot-scale constructed wetland system. This pilot-scale constructed wetland system consists of three types: subsurface-flow (SSF), surface-flow (SF) and a floating aquatic plant (FAP) system. Analysis of PLFA profiles indicated primarily eukaryotic organisms, including fungi, protozoa, and diatoms were observed in all three wetland systems. Biomarkers for Gram-negative bacteria were also detected in all samples analyzed while low proportions of biomarkers for Gram-positive bacteria were observed. Biomass content (total PFLA/sample) was highest in water samples collected from both SF and FAP system while highest metabolic activity was observed in FAP system. This is consistent with the observed highest metal removal rate in FAP system. Sequence analysis of the predominant PCR-DGGE DNA fragments showed 0.92 to 0.99 similarity indices to Beta-proteobacteria, Flavobacterium sp. GOBB3-206, Flexibacter-Cytophaga-Bacteroides group, and Gram-positive bacteria. Results suggest diverse microbial communities including microorganisms that may significantly contribute to biogeochemical elemental cycles.

Bacterial concentration reduction of food waste amended animal feed using a single-screw dry-extrusion process

Abstract Institutional food waste was collected, pulped, mixed with ground corn and soybean hulls and dry-extruded at temperatures of 110–135°C for no more than 30 s to produce animal feed. Raw food waste, pre- and post-extrusion animal feed, and commercial swine feed samples were collected aseptically and analyzed for total and fecal coliform, Enterococci, Staphylococci, heterotrophic, and non-specific anaerobic/facultative bacteria using standard culturing techniques. Bacterial concentrations recovered from post-extrusion animal feed were substantially reduced from all other sample types. Survival of heterotrophic and non-specific anaerobic/facultative bacteria in some post-extrusion samples indicated that extrusion techniques used in this study did not consistently sterilize animal feed. Results suggested that a single-screw, dry-extrusion process can reduce concentrations of potentially pathogenic bacteria, but that modification of extrusion techniques used in this study may be necessary for consistent optimal reduction of bacterial concentrations in food waste-amended animal feed.

Removal of N, P, BOD5, and Coliform in Pilot-Scale Constructed Wetland Systems

ABSTRACT Pilot-scale surface-flow (SF), subsurface-flow (SSF), and floating aquatic plant (FAP) constructed wetland system designs were installed and evaluated to determine the effectiveness of constructed wetlands to treat tertiary effluent wastewater in a Midwestern U.S. climate (central Illinois). Average ammonia-nitrogen (N) concentrations decreased approximately 50% in the SSF system design, suggesting that this design had the highest nitrification rate. Nitrate-N concentrations decreased by over 60% in the FAP system design, possibly due to dissimilatory reduction or plant uptake. Total phosphorus (P) concentration reductions of 25 to 40% were observed in all three system designs. Five-day biochemical oxygen demand (BOD5) and dissolved oxygen (DO) results suggested that biodegradation was highest in the SSF system design and lowest in the FAP system design. Greater than 90% concentration reductions of total coliform and E. coli recovered were also observed following treatment in all three system designs. The FAP system design appeared to yield the highest concentration reduction efficiency for E. coli, possibly due to increased sunlight and related bacteriocidal ultraviolet light exposure. Ongoing experiments will test regularly for a variety of vegetative, water quality, and biological conditions for longer time periods in order to gain a better understanding of the pilot constructed wetland system design kinetics.

Bacterial concentration reduction in swine waste amended livestock feed using a single-screw dry-extrusion process

A study was conducted to determine the eAciency of a dry-extrusion process to reduce or eliminate bacterial contamination of swine waste amended livestock feed. Separated swine waste solids were mixed with ground corn and soybean hulls and dry-extruded at temperatures of 110‐135∞C for no more than 30 s to produce animal feed. Swine waste, pre- and post-extrusion livestock feed, and commercial swine feed samples were collected aseptically and analysed for total coliform, Escherichia coli, fecal coliform, heterotrophic, and non-specific anaerobic/facultative bacteria using standard culturing techniques. Selected pre-extrusion feed samples were inoculated with liquid cultures of Bacillus stearothermophilus to test eAciency of the dry-extrusion process to eliminate heatresistant spore-forming bacteria. Bacterial concentrations recovered from post-extrusion livestock feed were significantly reduced from other sample types analysed. Based on these data, it is apparent that a single-screw, dry-extrusion process can consistently disinfect animal feed. However, careful monitoring of the extrusion process may be necessary for consistent sterilization. ” 2000 Elsevier Science Ltd. All rights reserved.

Environmental Health Insights into the 2010 Deepwater Horizon (BP) Oil Blowout

The Deepwater Horizon semi-submersible Mobile Offshore Drilling Unit (MODU), leased to BP (previously British Petroleum, now simply “BP”, with the previously-used promotional tagline of “beyond petroleum”) suffered an explosive “blowout” on April 20, 2010 which resulted in what is now the largest offshore oil spill in United States (U.S.) history, and currently estimated to be at least the second or perhaps third largest oil spill in global history. At the time of writing of this editorial (July 30, 2010), official estimates by the U.S. Department of the Interior (U.S. Geological Survey) indicated that 12,000–19,000 barrels (500–800,000 gallons at 42 U.S. gallons per barrel or 2–3 million liters) of oil were leaking per day for 87 days, for a current total estimate of 44–70 million gallons (167–265 million liters) spilled prior to placement of the current “secure” cap on July 15 (http://www.doi.gov/news/pressreleases/Flow-Rate-Group-Provides-Preliminary-Best-Estimate-Of-Oil-Flowing-from-BP-Oil-Well.cfm). However, some “unofficial” estimates are much larger, up do 100,000 barrels (4 million gallons or 15 million liters) leaking per day for a total release to date of up to 348 million gallons (1.32 billion liters) prior to July 15. While a significant amount of the oil was captured and recovered (up to 25,000 barrels per day at one point), this is higher than the lower initial estimates of the total daily spill amount, and may have represented less than 25% of the total daily spill amount. Efforts to drill relief wells continue, but unknown amounts of oil continue to leak from the cap and the surrounding seabed due to the tremendous pressures involved (estimated at 11–12,000 pounds per square inch or psi at the wellhead). To place this in perspective, the amount of oil released was roughly equivalent to the total amount of the 1989 Exxon-Valdez oil spill occurring every 3–64 days (based upon the largest to smallest Deepwater Horizon spill estimates, respectively). The largest known environmental oil release in global history, the intentional opening of valves on several oil tankers at the Sea Island oil terminal by Iraqi forces to slow the invasion of U.S. troops in 1991, released an estimated 520 million gallons (1.97 billion liters) into the Persian Gulf. The second largest release was another Gulf of Mexico (Camphece) exploratory well blowout in 1979, which released an estimated 100 million gallons (379 million liters) over a one-year period (http://www.envirowonk.com/content/view/68/1/). This means that the Deepwater Horizon spill rivals the second-largest known environmental oil release in global history, and may perhaps be even larger than current estimates indicate. A 2003 publication, Oil in the Sea III: Inputs, Fates and Effects (http://www.nap.edu/catalog.php?record_id=10388) estimated that the global marine oil seepage from natural sources ranges from 60–600 million gallons (227 million to 2.27 billion liters) per year, with best estimates at 180 million gallons (681 million liters) annually. Natural oil seepage typically far exceeds anthropogenic oil spills, but that is not the case during events such as the Deepwater Horizon spill. In fact, some have suggested that using the term “spill” to describe this event is a misnomer, since it is a continuing discharge of huge amounts of oil similar to (although perhaps far exceeding in volume) the year-long 1979 Camphece blowout event. It is interesting to compare the public perception of natural environmental disasters such as hurricanes in this region (most recently Katrina and Rita in 2005) to anthropogenic disasters such as the Deepwater blowout. The distinction is becoming less clear, partially due to humans placing themselves “in harm’s way” through increased population density in susceptible geographic regions (e.g., coastlines). There also appears to be a shift towards public perception that private insurance or governmental agencies should be responsible for mitigating damages rather than relying on individual, family or community resources, as has been the more traditional practice in the past. One challenge is that while ecological systems have developed an adaptive ability to deal with cyclic natural occurrences, there has been limited opportunity for the environment to adapt to infrequent events such as catastrophic oil spills. The environmental health implications of the Deepwater blowout are obviously far-reaching, with the clearest and most immediate for many being the affects on wildlife such as birds and aquatic mammals. The “Deepwater Horizon Response: The Official Site of the Deepwater Horizon Unified Command” website currently focuses on efforts to rescue and rehabilitate sea turtles and pelicans as well as including links to Environmental, Community, Assistance, Vessels of Opportunity, Wildlife Distress, Specialty Volunteer Training, Claims and Medical Support Hotlines (http://www.deepwaterhorizonresponse.com/go/site/2931/). Efforts to remediate damage to wildlife are ongoing, but admittedly address only a small fraction of the total volume of oil already released. Less obvious are the underwater effects, with attempts being made to track underwater plumes of oil in the region. The ultimate affects on aquatic organisms and aquatic-dependent organisms such as sea birds and aquatic mammals are currently unknown and difficult to predict. Unprecedented amounts of the oil dispersant Corexit EC9500 and EC9527A (more than 840,000 gallons or 2.6 million liters as of July 30, 2010) have been used to break up the oil into small droplets, which, theoretically, should enhance natural biochemical and physical/chemical remediation. However, the toxicity of the dispersants has been questioned, with the dispersants used rated as 10–20 times more toxic than other options approved by the U.S. Environmental Protection Agency (USEPA). On May 26, the USEPA and U.S. Coast Guard (USCG) ordered BP to reduced dispersant use volume by 75% (to a total of 15,000 gallons per day) and eliminate surface water use of dispersant entirely unless authorized by the USCG (http://www.epa.gov/bpspill/dispersants.html). Components of both oil and dispersants are volatile to varying degrees (evaporating at typical ambient “normal” environmental temperatures), which means that they are carried into the atmosphere in vapor form, which may be inhaled by humans and other organisms. There have also been reports of “raining oil” in Florida and Louisiana, perhaps due to a mixture of oil and dispersants being entrained into the atmosphere in aerosol form and carried to the earth by precipitation. The American Public Health Association (APHA) Environment Section webpage (http://www.apha.org/programs/environment/) includes links to the Centers for Disease Control and Prevention (CDC) Emergency Preparedness and Response site (including ”What to Expect from the Oil Spill and How to Protect your Health” and “Information for Coastal Residents” webpages. The latter focuses on food, air quality and water quality concerns for coastal residents. The APHA site also links to CDC Heath Surveillance information among the five Gulf Coast States of Texas, Louisiana, Mississippi, Alabama and Florida well as to the National Institute of Environmental Health Sciences (NIEHS) “Safety and Training of Oil Spill Response Workers” site. Oil spill response workers have reported health issues related to clean-up efforts and response efforts were delayed during hurricane Alex (June 29, 2010). Two independent U.S. Congressional Hearings were held during June 2010 on the Health Effects of the Oil Spill, including a U.S. Senate Committee on Health Education Labor and Pensions on June 15 and a U.S. House of Representatives Committee on Energy and Commerce Hearing on June 16. Both Hearings included testimony of witnesses from the Department of Health and Human Services (HHS), the National Institute for Occupational Safety and Health (NIOSH), the NIEHS, and the Food and Drug Administration (FDA). It is also unclear what impact the solid waste generated from the blowout and from clean-up operations will have on environmental and public health. Currently, it appears that oil-contaminated solid waste is being diverted to municipal waste landfills. Since the waste may contain components or exhibit characteristics of hazardous waste, it would appear that disposal in a hazardous waste (secure) landfill or perhaps environmentally-responsible incineration in conjunction with energy recovery would be a more appropriate option. The Deepwater Horizon blowout is one of the largest global oil spills in history, with far-reaching environmental and economic consequences. The environmental health effects of the Deepwater Horizon blowout event are likely to be felt for decades, similarly to the Exxon-Valdez spill. Perhaps the societal impact of the constant media attention on this event, including the unique “live-feed” of video images from the wellhead blowout will help the global community, and the United States specifically, to re-evaluate the environmental health hazards and risks associated with our current oil dependence.

Preliminary evaluation of metals removal in three pilot‐scale constructed wetland systems

Pilot‐scale surface‐flow, subsurface‐flow and floating aquatic plant constructed wetland system designs were installed and evaluated to determine the effectiveness of constructed wetlands to immobilize and remove metals such as cadmium, zinc, copper, chromium, lead and nickel in tertiary effluent wastewater in a Midwestern US climate (central Illinois). Following wetland treatment, average concentrations of copper decreased from 56.6μg/l in influent to 7.9μg/l (86.0 per cent reduction) in the FAP system, 9.2μg/l (83.7 per cent reduction) in the SSF system and 11.0μg/l (80.6 per cent reduction) in the SF system, respectively. Results of ANOVA indicated that differences in concentration reduction of copper among the three wetlands were not statistically significant. The average concentration of chromium decreased from 1.31μg/l in influent to 0.4μg/l (69.5 per cent reduction) in all system designs. Copper concentrations were reduced consistently with increasing wetland retention time, with most of concentration reduction having occurred in the first wetland cell for all system designs.

Environmental Health Resilience

Global Human Populations The capacity of the Earths environment to support increasing and expanding human populations has been questioned at least for hundreds of years, but never more than in the mid to late 20th Century and early 21st Century. Global human population now exceeds seven billion and continues to increase at an unprecedented rate. Estimates of future (2050) human populations on Earth range from a low of about 7.4 billion to a high of 10.6 billion (“United Nations World Population to 2300”, 2004 accessed at http://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf). Current human populations already place an extreme burden on global environmental resources, including air, water and food quality as well as increasing challenges related to human waste management and disease prevention, control and treatment. In fact, some have proposed that humans have entered the “anthropocene”, an age in which the global environment is dominated by human activities (http://www.sciencedaily.com/releases/2012/11/121101131609.htm). Climate change and expanding human populations contribute to increased risk of transmission of infectious and non-infectious disease. Developing nations with huge human populations such as China and India are benefitting from increased economic globalization, allowing for increased availability of personal luxuries such as automobiles, which in turn results in increased pollution and further depletion of natural resources such as global oil reserves. Increasing availability to global resources also may contribute to global conflict over environmental resources such as oil, water and food. In the United States, 2013 was the hottest year on record. Average global temperatures are also on the rise, with Australia being another prime example. Globally, 2012 was the tenth hottest year on record since data collection began in 1880 (http://www.ncdc.noaa.gov/sotc/global/2012/13). Many people are now starting to question the ability of human populations to continue to grow, and perhaps even for humans continue to exist on the planet without significant changes in the way that we interact with our global environment. Others point out that dire predictions of the fragility of humanity have been made for thousands of years and that humans have continued to survive and even grow in spite of these challenges.

Preliminary water quality assessment of Spunky Bottoms restored wetland

The approximately 1200-acre “Spunky Bottoms” wetland in Southern Illinois has been undergoing restoration to conditions prior to levying of the Illinois River and draining of adjacent floodplain for intensive agriculture (circa 1900). As part of a long-term water quality impact assessment of this restoration project, baseline water quality monitoring was conducted soon after restoration began. During this baseline/preliminary assessment, water samples were taken every 2–4 weeks from 10 sampling wells and seven surface water sites throughout the wetlands area for a period of 18 months. Measured parameters include nutrients (nitrate (NO3 −) and phosphate (PO4 3−), cations and anions (SO4 2 −, Cl−, Na+, K+, Mg2 +, Ca2 +) commonly found in surface and well water, trace metals (Al, Cd, Cu, Fe, Mn, Ni, Pb, Se, Zn), total dissolved solids (TDS), pH, and trace organics (triazine herbicides and their metabolites). In general, highest concentrations of ions were found in the southwest and northeast perimeter of the wetland area for both surface and ground water samples. Primarily low concentrations of heavy metals and organic compounds were found throughout the wetland sampling area. Distribution of NO3 −-N suggests that this restored wetland, even at its infant age, may still contribute to biogeochemical (particularly N) element cycling. Continued monitoring and further research is necessary to determine long-term specific contribution of restored wetland to biogeochemical cycles.In the present work changes in the adsorption of the pesticide chlorpyrifos-methyl (CLP-m) on soil colloids induced by application of surfactants were determined using a batch equilibrium method. The surfactants used were sodium dodecyl sulphate (SDS), Tween 20, and dihexadecyldimethylammonium bromide (DHAB). The adsorption isotherms of CLP-m in aqueous medium and in surfactant solutions at concentration equal to the critical micelle concentration (CMC) fitted the Freunlich adsorption equation generally with R(2) values greater than 0.96. While the addition of SDS and DHAB decreased the pesticide adsorption, the addition of Tween 20 increased the pesticide adsorption. The increases or decreases in the adsorption in the experiment revealed that the behavior of CLP-m in soil water-systems mainly depends on the type of surfactant. Moreover water solubility of CLP-m changes by the three surfactants below and above their CMC were studied. While the solubility of CLP-m was enhanced by SDS both below and above the CMC, the solubility of the pesticide was enhanced by DHAB only above the CMC. Tween 20 did not influence the solubility of CLP-m.