Diesel-powered equipment is known to emit significant quantities of fine particulate matter to the atmosphere. Numerous organic compounds can be adsorbed onto the surfaces of these inhalable particles, among which polycyclic aromatic hydrocarbons (PAHs) are considered potential occupational carcinogens. Guidelines have been established by various agencies regarding diesel emissions and various control technologies are under development. The purpose of this study is to identify, quantify and compare the organic compounds in diesel particulate matter (DPM) with the diesel fuel and engine oil used in a non-road diesel generator. Approximately 90 organic compounds were quantified (with molecular weight ranging from 120 to 350), which include alkanes, PAHs, alkylated PAHs, alkylbenzenes and alkanoic acids. The low sulfur diesel fuel contains 61% alkanes and 7.1% of PAHs. The identifiable portion of the engine oil contains mainly the alkanoic and benzoic acids. The composition of DPM suggests that they may be originated from unburned diesel fuel, engine oil evaporation and combustion generated products. Compared with diesel fuel, DPM contains fewer fractions of alkanes and more PAH compounds, with the shift toward higher molecular weight ones. The enrichment of compounds with higher molecular weight in DPM may be combustion related (pyrogenic).

Literature on NH₃ and H₂S emissions from swine production facilities in North America was reviewed, and a meta-analysis was conducted on measured emissions data from swine houses and manure storage facilities as well as concentration data in the vicinity of swine production facilities. Results from more than 80 studies were compiled with results from the 11 swine sites in the National Air Emissions Monitoring Study (NAEMS). Data across studies were analyzed statistically using the MIXED procedures of SAS. The median emission rates from swine houses across various production stages and manure handling systems were 2.78 and 0.09 kg/yr per pig for NH₃ and H₂S, respectively. The median emission rates from swine storage facilities were 2.08 and 0.20 kg/yr per pig for NH₃ and H₂S, respectively. The size of swine farm that may trigger the need to report NH₃ emissions under the Emergency Planning and Community Right-to-Know Act (EPCRA) is 3,410 pigs on the basis of the median NH₃ emission rate (4.86 kg/yr per pig), but the threshold can be as low as 992 pigs on the basis of the 90th-percentile emission rates (16.71 kg/yr per pig). Swine hoop houses had significantly higher NH₃ emission rate (14.80 kg/yr per pig) than other manure-handling systems (P < 0.01), whereas deep-pit houses had the highest H₂S emission rate (16.03 kg/yr per pig, P = 0.03). Farrowing houses had the highest H₂S emission rate (2.50 kg/yr per pig), followed by gestation houses, and finishing houses had the lowest H₂S emission rate (P < 0.01). Regression models for NH₃ and H₂S emission rates were developed for finishing houses with deep pits, recharge pits, and lagoons. The NH₃ emission rates increased with increasing air temperature, but effects of air temperature on H₂S emission rates were not significant. The recharge interval of manure pits significantly affected H₂S but not NH₃ emission rates. The H₂S emission rates were also influenced by the size of the operation. Although NH₃ and H₂S concentrations at the edge of swine houses or lagoons were often higher than corresponding acute or intermediate minimum risk levels (MRL), they decreased quickly to less than corresponding chronic or intermediate MRL as distances from emission sources increased. At the distances 30 to 1,185 m from emission sources, the average ambient concentrations for NH₃ and H₂S were 46 ± 46 µg/m³ and 4.3 ± 8.6 µg/m³ respectively.

The tapered element oscillating microbalance (TEOM) is one type of continuous ambient particulate matter (PM) monitor. Adsorption and desorption of moisture and semivolatile species may cause positive or negative artifacts in TEOM PM mass measurement. The objective of this field study was to investigate possible uncertainties associated with TEOM measurements in the poultry operation environment. For comparisons of TEOM with filter-based gravimetric method, four instruments (TEOM-PM₁₀, low-volume PM₁₀ sampler, TEOM-PM_2.5, and PM_2.5 speciation sampler) were collocated and tested inside a poultry house for PM_2.5 and PM₁₀ (PM with aerodynamic equivalent diameter ≤2.5 and ≤10 μm, respectively) measurements. Fifteen sets of 24-hr PM₁₀ concentrations and 13 sets of 24-hr PM_2.5 measurements were obtained. Results indicate that compared with filter-based gravimetric method, TEOM gave significantly lower values of both PM₁₀ and PM_2.5 mass concentrations. For PM₁₀, the average ratio of TEOM to the gravimetric method was 0.936. For PM_2.5, the average ratio of TEOM to the gravimetric method was 0.738. Particulate matter in the poultry houses possibly contains semivolatile compounds and moisture due to high levels of relative humidity (RH) and gas pollutants. The internal heating mechanism of the TEOM may cause losses in mass through volatilization. To investigate the effects of TEOM settings on concentration measurements, the heaters of two identical TEOMs were set at 50 °C, 30 °C, or no heating at all. They were collocated and tested for total suspended particle (TSP), PM₁₀, and PM_2.5 measurements in layer house for 6 weeks. For all TSP, PM₁₀, and PM_2.5 measurements, the internal TEOM temperature setting had a significant effect (P < 0.05). Significantly higher PM mass concentrations were measured at lower temperature settings. The effects of environmental (i.e., temperature, RH, NH₃ and CO₂ concentrations) and instrumental (i.e., filter loading and noise) parameters on PM measurements were also assessed using regression analysis.