California dairies house approximately 1.8 million lactating and 1.5 million dry cows and heifers. State air regulatory agencies view these dairies as a major air pollutant source, but emissions data are sparse, particularly for volatile organic compounds (VOCs). The objective of this work was to determine VOC emissions from lactating and dry dairy cows and their waste using an environmental chamber. Carbon dioxide and methane were measured to provide context for the VOCs. VOCs were measured by proton-transfer-reaction mass spectrometry (PTR-MS). The compounds with highest fluxes when cows plus waste were present were methanol, acetone + propanal, dimethylsulfide, and m/z 109 (likely 4-methyl-phenol). The compounds with highest fluxes from fresh waste (urine and feces) were methanol, m/z 109, and m/z 60 (likely trimethylamine). Ethanol fluxes are reported qualitatively, and several VOCs that were likely emitted (formaldehyde, methylamine, dimethylamine) were not detectable by PTR-MS. The sum of reactive VOC fluxes measured when cows were present was a factor of 6-10 less than estimates historically used for regulatory purposes. In addition, ozone formation potentials of the dominant VOCs were -10% those of typical combustion or biogenic VOCs. Thus dairy cattle have a comparatively small impact on ozone formation per VOC mass emitted.

There are approximately 2.5 million dairy cows in California. Emission inventories list dairy cows and their manure as the major source of regional air pollutants, but data on their actual emissions remain sparse, particularly for smog‐forming volatile organic compounds (VOCs) and greenhouse gases (GHGs). We report measurements of alcohols, volatile fatty acids, phenols, and methane (CH4) emitted from nonlactating (dry) and lactating dairy cows and their manure under controlled conditions. The experiment was conducted in an environmental chamber that simulates commercial concrete‐floored freestall cow housing conditions. The fluxes of methanol, ethanol, and CH4 were measured from cows and/or their fresh manure. The average estimated methanol and ethanol emissions were 0.33 and 0.51 g cow−1 h−1 from dry cows and manure and 0.7 and 1.27 g cow−1 h−1 from lactating cows and manure, respectively. Both alcohols increased over time, coinciding with increasing accumulation of manure on the chamber floor. Volatile fatty acids and phenols were emitted at concentrations close to their detection limit. Average estimated CH4 emissions were predominantly associated with enteric fermentation from cows rather than manure and were 12.35 and 18.23 g cow−1 h−1 for dry and lactating cows, respectively. Lactating cows produced considerably more gaseous VOCs and GHGs emissions than dry cows (P < 0.001). Dairy cows and fresh manure have the potential to emit considerable amounts of alcohols and CH4 and research is needed to determine effective mitigation.

Sodium bisulfate (SBS) is extensively used in the poultry industry to reduce ammonia and bacterial levels in litter. It is also used in the dairy industry to reduce bacterial counts in bedding and ammonia emissions, preventing environmental mastitis and calf respiratory stress. The present study measured the effect of SBS on the air emission of ammonia, amine, and alcohol from a dairy slurry mix. Amine flux was undetectable (<5 ng L(-1)) across treatments. Application of SBS decreased ammonia, methanol, and ethanol emissions from fresh dairy slurry. Ammonia emissions decreased with increasing levels of SBS treatment. The 3-d average ammonia flux from the control (no SBS applied) and the three different SBS surface application levels of 0.125, 0.250, and 0.375 kg m(-2) were 513.4, 407.2, 294.8, and 204.5 mg h(-1) m(-2), respectively. The ammonia emission reduction potentials were 0, 21, 43, and 60%, respectively. Methanol and ethanol emissions decreased with an increase in the amount of SBS applied. The 3-d average methanol emissions were 223.7, 178.0, 131.6, and 87.0 mg h(-1) m(-2) for SBS surface application level of 0, 0.125, 0.250, and 0.375 kg m(-2), with corresponding reduction potentials of 0, 20, 41, and 61, respectively. Similar emission reduction potentials of 0, 18, 35, and 58% were obtained for ethanol. Sodium bisulfate was shown to be effective in the mitigation of ammonia and alcohol emissions from fresh dairy slurry.

23Mobile. +260 96 3088750 | +1 936-661-6885 24 ABSTRACT 25 Chronic kidney disease of unknown etiology (CKDu) was first recognized in Sri Lanka in the early 26 1990s, and since then it has reached epidemic levels in the North Central Province of the country.27 The prevalence of CKDu is reportedly highest among communities that engage in chena and paddy 28 farming, which is most often practiced in the dry zone including the North Central and East Central 29 Provinces of Sri Lanka. Previous studies have suggested varied hypotheses for the etiology of 30 CKDu; however, there is not yet a consensus on the primary risk factors, possibly due to disparate 31 study designs, sample populations, and methodologies. The goal of this pilot case-control study 32 was to evaluate the relationships between key demographic, cultural, and occupational variables 33 as risk factors for CKDu, with a primary interest in pesticide exposure both occupationally and 34 through its potential use as an ingredient in brewed kasippu alcohol. A total of 56 CKDu cases 35 and 54 control individuals were surveyed using a proctored, self-reported questionnaire. 36 Occupational pesticide exposure and alcohol consumption were not found to be significant risk 37 factors for CKDu. However, a statistically significant association with CKDu was observed with 38 chewing betel (OR: 6.11, 95% CI: 1.93, 19.35), age (OR: 1.07, 95% CI: 1.02, 1.13), owning a pet 39 dog (OR: 3.74, 95% CI: 1.38, 10.11), water treatment (OR: 3.68, 95% CI: 1.09, 12.43) and pests 40 in the house (OR: 5.81, 95% CI: 1.56, 21.60). The findings of this study suggest future research 41 should focus on practices associated with chewing betel, potential animal interactions including 42 pests in the home and pets, and risk factors associated with water.