Is inhaled ammonia neurotoxic?

Remote sensing and in situ measurements of methane and ammonia emissions from a megacity dairy complex: Chino, CA

Methane (CH₄) and ammonia (NH₃) directly and indirectly affect the atmospheric radiative balance with the latter leading to aerosol generation. Both have important spectral features in the Thermal InfraRed (TIR) that can be studied by remote sensing, with NH₃ allowing discrimination of husbandry from other CH₄ sources. Airborne hyperspectral imagery was collected for the Chino Dairy Complex in the Los Angeles Basin as well as in situ CH₄, carbon dioxide (CO₂) and NH₃ data. TIR data showed good spatial agreement with in situ measurements and showed significant emissions heterogeneity between dairies. Airborne remote sensing mapped plume transport for ∼20 km downwind, documenting topographic effects on plume advection. Repeated multiple gas in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1 × 10⁵ kg CH₄, 2.2 × 10⁵ kg NH₃, and 2.3 × 10⁷ kg CO₂, suggesting 2300, 4000, and 2100 head of cattle, respectively, and Chino Dairy Complex emissions of 42 Gg CH₄ and 8.4 Gg NH₃ implying ∼200k cows, ∼30% more than Peischl et al. (2013) estimated for June 2010. Far-field data showed chemical conversion and/or deposition of Chino NH₃ occurs within the confines of the Los Angeles Basin on a four to six h timescale, faster than most published rates, and likely from higher Los Angeles oxidant loads. Satellite observations from 2011 to 2014 confirmed that observed in situ transport patterns were representative and suggests much of the Chino Dairy Complex emissions are driven towards eastern Orange County, with a lesser amount transported to Palm Springs, CA. Given interest in mitigating husbandry health impacts from air pollution emissions, this study highlights how satellite observations can be leveraged to understand exposure and how multiple gas in situ emissions studies can inform on best practices given that emissions reduction of one gas could increase those of others.

Ammonia release from heated 'street' cannabis leaf and its potential toxic effects on cannabis users

AIMS

To use selected ion flow tube mass spectrometry (SIFT-MS) to analyse the molecular species emitted by heated 'street' cannabis plant material, especially targeting ammonia.

MATERIALS AND METHODS

Samples of 'street' cannabis leaf, held under a UK Home Office licence, were prepared by finely chopping and mixing the material. The samples were then heated in commercially available devices. The air containing the released gaseous compounds was sampled into the SIFT-MS instrument for analysis. Smoke from standard 3% National Institute on Drug Abuse (NIDA) cannabis cigarettes was also analysed.

FINDINGS

For 'street' cannabis, ammonia was present in the air samples from the devices at levels approaching 200 parts per million (p.p.m.). This is compared with peak levels of 10 p.p.m. using NIDA samples of known provenance and tetrahydrocannabinol content (3%). Several other compounds were present at lower levels, including acetaldehyde, methanol, acetone, acetic acid and uncharacterized terpenes.

CONCLUSIONS

Awareness of the risks of inhaling the smoke directly from burning cannabis has led to the development of a number of alternative methods of delivery, which are claimed to be safer than direct smoking. Ammonia at toxic levels is produced from heating 'street' cannabis in these commercially available devices. Thus, the use of these devices to deliver 'street' cannabis is now open to question and further research is needed to investigate their safety.

Chronic Ammonia Inhalation and Interstitial Pulmonary Fibrosis: A Case Report and Review of the Literature

Ammonia is an irritant gas with a characteristic pungent odor, which is widely used in industry. Inasmuch as ammonia is highly soluble in water and, upon inhalation, is deposited in the upper airways, occupational exposures to ammonia have commonly been associated with sinusitis, upper airway irritation, and eye irritation. Acute exposures to high levels of ammonia have also been associated with diseases of the lower airways and interstitial lung. In this study, the authors report on a patient with long-term, repetitive occupational exposure to ammonia at levels at or above odor recognition who developed interstitial lung disease. The scientific literature on inhaled ammonia exposure is reviewed and discussed. The authors conclude that the taking of a careful occupational exposure history for patients presenting with shortness of breath associated with ammonia exposure may assist with an early diagnosis, thus allowing for treatment early in the disease process and prevention of further exposure.

Function testing for chemical brain damage: a review

Testing of neurobehavioral functions for evaluation of the effects of chemicals on the human brain from community (i.e., environmental) exposures is logical and may be a preferred initial step. Sensitivity is improved (1) by adjusting individual tests for influential factors, found by regression modeling and by retaining significant coefficients; and (2) by the calculation of predicted values for each test for each subject. This two-part approach allows for adjustments in age, sex, educational level, and other factors before comparisons are made. Visual fields, color discrimination, reaction time, balance, and digit symbol are the most sensitive tests, followed by 6 sensitive psychological tests and less-discriminating physiological measurements. Hydrogen sulfide, polychlorinated biphenyls, and arsenic are the most toxic chemicals, followed by chlorine, chlorpyrifos, formaldehyde, nickel carbonyl, and ammonia. The least toxic chemicals, which are hydrochloric acid and chlorine, were determined 7 wk following a community spill. The least toxic chemical among those identified herein is methyl ter butyl ether.