Composition of human excreta--a case study from Southern Thailand.

In Thailand, human excreta might be recycled into agricultural soils as a supplement to commercial fertiliser and thereby enrich the general fertility of the soils. However, for Thailand an adequate knowledge of the quality of human excreta, in order to assess its fertiliser potential, is not available. A literature survey revealed only very limited information of the chemical composition and generation rate of human excreta in South East Asia. Data from other parts of the world also lacked specific information on collection and analytical methods, or the studies were typically 20-30 years old. In the present study the composition of human excreta has been studied in three case study areas in Southern Thailand: Kuan Lang, Phattalung and Prik. The inhabitants of the three areas represent people of Southern Thailand by age, sex, occupation, religion and type of residence. Human excreta was collected and stored for 1 week from five persons in each area, who each had their own toilet and collection bucket. In parallel, a septic tank at the Observation and Protection (O&P) Centre of Songkhla (a boys prison institution) adjacent to the three study areas was used as a daily sampling point, to obtain data on average amounts of human excreta and chemical composition. Information on average values of generation rate and chemical composition was obtained as well as inter-human variation. However, no significant variation was found between the results for human excreta at the O&P Centre or from the 15 individuals. Furthermore, there was no significant influence of age, sex, occupation or religion on the chemical composition. The only significant variation was that the older people excreted larger amounts of total wet matter than the younger, which could be due to a higher water intake, in order to reduce the risk of constipation. The generation rate found was 0.6-1.2 1 urine/cap/day and 120-400 g wet faeces/cap/day. The generation rate of the elements in the excreta was 7.6-7.9 g N/cap/day, 1.6-1.7 g P/cap/day, 1.8-2.7 g K/cap/day, 1.0-1.1 g S/cap/day, 0.75-1.5 g Ca/cap/day, 0.25-0.4 g Mg/cap/day, 9-16 mg Zn/cap/day, 1.4-1.5 mg Cu/cap/day, 0.3 mg Ni/cap/day, 0.02-0.03 mg Cd/cap/day, 0.07-0.14 mg Pb/cap/day, 0.01 mg Hg/cap/day and 0.8-1.1 mg B/cap/day. The metals (Ca, Mg, Zn, Cu, Ni, Cd, Pb, Hg) are mainly excreted via the faeces and the remaining elements (N, P, K, S, B) are mainly excreted via the urine. It can be concluded that human excreta constitutes a large fertiliser resource, which presently is not utilised in Thailand.

Cadmium in soil and terrestrial biota, with emphasis on the Danish situation.

The cadmium load on the soil and terrestrial biota in the industrialized countries appears to be on the increase. Due to a relatively high mobility of this metal in the soil-plant system, the likely gradual increase in soil concentrations will influence the cadmium load on organisms in the terrestrial biota. It might be too early to predict the actual rate of increase in the cadmium load on specific organisms but some attempts to do so have suggested an annual increase rate of 0.5-2% in the human food intake of the metal. Although the present cadmium pollution of the environment at large is not yet crucial, the most sensitive species, man and other long-lived mammals, might soon need introduction of countermeasures to seriously reduce the load of this toxic metal. The most feasible countermeasures to be taken are reductions in emission to air directly or indirectly via reduction of the indiscriminate use of the metal for common consumer goods. A decrease of the inflow to soils in phosphate fertilizer may be more difficult to curb, but a reduced fertilization rate on most areas might be possible without loss of fertility. Sludge may not be a major source of cadmium nationally, but may locally significantly increase the inflows to agriculture (Statens Naturvårdsverk, 1978; Miljøstyrelsen, 1980; Umweltbundesamt, 1981; Department of the Environment, 1980.

Treatment of nickel dermatitis. (The influence of tetraethylthiuramdisulfide (Antabuse) on nickel metabolism).

Nickel is the most common cause of allergic contact dermatitis in females. The dermatitis can be maintained both by direct contact and by ingestion of nickel. In 9 out of 17 patients suffering from dermatitis, a diet with a low nickel content has improved their condition. Eleven patients with chronic nickel hand dermatitis were given a daily dosage of 200 to 400 mg of tetraethylthiuramdisulfide (Antabuse). Antabuse is metabolized to the nickel chelating substance sodium diethyldithiocarbamate. In eight patients, the dermatitis cleared. Measurements of serum and urine nickel were performed in six patients. One week after the start of the Antabuse treatment, the urine nickel rose from 1 to 3.6 micrograms per 24 hours to 8.3 to 76.0 micrograms per 24 hours. The serum nickel rose from 0.26 to 0.80 micrograms per 1 to 2.0 to 7.7 micrograms per 1. In four patients the serum nickel exhibited a declining tendency during the treatment period. The results suggest that Antabuse is able to reduce the nickel deposits in man.

Antabuse treatment of nickel dermatitis. Chelation--a new principle in the treatment of nickel dermatitis.

Eleven nickel-hypersensitive patients with chronic, dyshidrotic hand eczema aggravated by oral challenge with 0.6-2.5 mg nickel were treated with 100 mg tetraethylthiuramdisulfide (Antabuse) two to four times daily for 4-10 weeks. Nine of the patients experienced a flare of the dermatitis shortly after initiation of the treatment. During the course of treatment the dermatitis of seven patients cleared, improvement was seen in two patients, and in two the dermatitis remained unchanged. Flare was seen in six patients when the treatment was discontinued. Seven patients experienced side effects such as fatigue, headache and dizziness. The treatment of four patients was discontinued due to side effects. During the treatment high levels of nickel were found in the serum and urine.

Interlaboratory comparison of lead and cadmium in blood, urine, and aqueous solutions.

Analysis for lead and cadmium in biological liquids (blood and urine) is difficult. Results of such analyses from five laboratories are compared for samples with known additions of lead and cadmium. The data, evaluated in terms of inter- and intralaboratory reproducibility and accuracy, suggest that laboratories should voluntarily participate in quality control programs. Users of routine laboratories are advised to use their own quality control program.

Low nickel diet in the treatment of patients with chronic nickel dermatitis.

Of 28 patients with chronic nickel dermatitis 17 experienced aggravation following oral ingestion of 2.5 mg nickel, but not a placebo tablet. The dermatitis of 9 of the 17 patients improved during a period of 6 weeks on a low nickel diet. The dermatitis of 7 of the 9 patients flared again when a normal diet was resumed. Nickel excretion over a 24-h period was measured for 14 of the 17 patients by atomic absorption spectrophotometry before, during, and after the diet. Reduced excretion was seen during the diet with no statistically significant difference between patients whose dermatitis improved during the diet and those whose dermatitis showed no change.