Ground applications

The 23 line drawings in [130] are very helpful for most routine bonding and grounding applications and for many years have been reproduced in NPCA 803 [6j. The following two sections cover general nonroutine applications. Chapters 5 and 6 of this book address specific grounding applications and special cases where electrical continuity may be unexpectedly lost. 

Collection stations were located at various distances from the point of application up to 2600 ft in the aerial studies, 1300 ft in the ground application studies and 1000-1500 ft in the orchard studies. 

There appears to be rather limited reporting of results from field trials of thermally modified wood. Welzbacher and Rapp (2004) have given preliminary data on an ongoing field trial of a number of heat-treatment processes with softwood and hardwoods up to 2.5 years duration. All workers in this area are of the opinion that heat-treated wood is suitable only for out-of-ground applications (Hazard Classes 1, 2 and 3). 

The ground application was made with a tractor equipped with a rear mounted boom sprayer. The aerial applications were made with a- helicopter equipped with a boom. The hand-gun applications were made with a commercial high pressure hose-nozzle sprayer. 

Applicators. The workers involved in the ground applications of carbaryl received considerably less exposure than the mixer-loaders. Most of the exposure was to the hands and was attributed to adjusting the nozzles on the spray equipment. Thus, for the ground application of the 80S formulation, the total HDE was 1.6 mg/h and the HDE to the hands was 1.5 mg/h. For a similar application of Sevimol-4, the total HDE was 2.8 mg/h and the HDE to the hands was 2.7... 

The aerial applicators also had considerably less exposure than the mixer-loaders. Again, most of this exposure was to the hands and was acquired from adjusting nozzles on the spray equipment. For the 80S and the XLR formulations, the total HDE s were 7.4 and 3.4 mg/h, respectively, and almost 100% of the exposure was to the hands in both cases. Here, as for the ground application, the highest HDE was obtained from Sevimol-4 because of the more frequent plugging of the spray nozzels. Thus the total HDE for Sevimol-4 was 26.5 mg/h, and the HDE on the hands was 25.7 mg/h. 

Bystanders. The bystander had the lowest exposure to carbaryl of all the workers monitored. In keeping the bystander within 100 feet and downwind of the ground applicator, the bystander often had to walk into the field while it was being treated. This practice resulted in exposure when the hands of the bystander touched the crop foliage. Thus, with peas, there was no exposure because the plants were too small at the time of spraying for any inadvertent contact, but with relatively mature potatoes, measurable residues were deposited on the bystander. For example, when 80S was applied to this crop, the bystander had a total HDE of 0.5 mg/h... 

D. The participants included 26 ground applicators in North Dakota after a single exposure and 17 aerial applicators in Washington during intermittent exposure. The objective was to ascertain worker exposure base-levels of 2,4-D under normal use conditions. Mean daily urinary excretion of 2,4-D by workers involved in aerial applications was 0.006 mg/kg body weight for pilots and 0.02 mg/kg for mixer/loaders from intermittent exposure. Workers involved in ground applications had maximum mean one-day 2,4-D urinary excretion of 0.002, 0.003, and 0.004 mg/kg, respectively, for applicators, mixer/loaders, and mixer/loader/applicators from a one-time exposure. The Ej/2 (half-elimination time for total... 

D amount excreted) values ranged from 35 to 48 h for the onetime exposed workers making ground applications. A correlation existed between 2,4-D excreted in the urine vs. worker duty for personnel involved in both the aerial and ground applications and... 

D excreted in urine from workers of ground application only vs. hours of exposure and vs. amount of 2,4-D applied. There was no apparent correlation between age (except where worker duty and age were correlted) weight, clothing, or 2,4-D formulation. 

Ground application workers. Urinary excretion samples from ground applicators and mixer/loaders from North Dakota were taken on 6 consecutive days after a single 2,4-D exposure. Most participants provided one preexperimental urine sample, which contained from nondetectable quantities to 0.4 ppm 2,4-D. 

Table V. 1980 2,4-D 1-Day Exposure to Ground Applicators in North Dakota... 

Figure 1. Relationship between hours of 2,4-D exposure and excretion rate. Key -----, mixer/loaders, excretion —1.8 + 3.8 h (r 0.78 ) ---------, ground applicators, excretion 0.55 + 2.2 h (r 0.68")...

One-half of all ground applicators exposed to 2,4-D had maximum daily excretions of <0.002 mg/kg (Table VI), which is probably more indicative of the exposure level for an average worker rather than the >0.003 mg/kg maximum mean given in Table V for all ground workers. 

Figure 4. Percent of daily 2,4-D excretion from a single exposure for the first 6 days (% 0.04 15 d — 1.1 d3 0.12 d4 (r 0.99") based on ground applications).

Commercial herbicide handlers who use the herbicides for ground application... 

Commercial aerial applicator Commercial aerial mixer/loader All commercial aerial Commercial ground applicator Commercial ground mixer/loader All commercial ground 7 Mixer/Loader applicator 7 Applicator Mixer/Loader... 

This study found that some crew members involved in the aerial application of 2,4-D for forestry purposes absorbed low levels of 2,4-D, but the doses as indicated by urine analyses were several orders of magnitude below the 24 mg/kg noobservable-effect-level determined in toxicology studies. These results are in agreement with those of Nash et al. (1982). The doses were comparable to those found in an earlier test involving aerial application of 2,4,5-T but were substantially lower than those found for ground application of that herbicide (Lavy et al., 1980). 

Sorption heat pipe is a novelty and combines the enhanced heat and mass transfer typical for conventional heat pipe with sorption phenomena in the sorbent structure. The sorption heat pipe parameters are insensitive to some g acceleration and such heat pipe can be suggested for space and ground application. 

The presented method of clinical-and-toxicological analysis is especially important in those situations when at the moment of crime it is impossible to identify the nature of the act of terrorism using known methods of chemical analysis as it was occurred in conditions of tragedies in Japan. The noted coincidence of victims as the result of application of sarin on solid aerosol-carrier possibly proves the elaboration of median lethal inhalation doses, thoroughly prepared composition in conditions of ground application (Matsumoto) and closed space (Tokyo Subway). 

---