Spatial Temporal Variation of Lead Concentration in the Chao Phraya River from Changwat Nakhon Sawan to Changwat Samut Prakan, 1991

Yukhongkhram, Amphan

Major Field of Environmental Science, Interdisciplinary Graduate Program, Kasesart University, Thesis of Master Degree, Bangkok 10900, Thailand

Abstract

An investigation on the Spatial Temporal Variation of Lead Concentration in the Chao Phraya River from Changwat Nakhon Sawan to Changwat Samut Prakan was conducted during 1970 - 1989 ( 10 years). The study area was divided into two zones of the Chao Phraya Basin. The upstream area includes 18 stations, from Changwat Nakhon Sawas to Changwat Pathum Thani and the downstream zone consists of 8 stations, from Changwat Nondhaburi to Changwat Samut Prakan.

The lead concentrations found in the upstream were recorded 85 from 139 average values which 23 average values or 17 percent were higher than the standard. In 1986, lead contamination generally found at every station, but in 1980 only one station in Changwat Pranakhon Sriayudhya was found. The result of this study was that the distribution of lead appeared to be found any station any time, and the tendency of lead contamination in the latest year (1989) showed the increment.

The status of lead concentrations in the downstream was reported 58 out of 73 average values of which 33 percent or 24 average values were above the standard. The periods that the lead presented at all 8 stations were in 1982 - 1984, 1986, 1989 and only one station was displayed in 1981. The distribution of lead showed the same pattern as in the upstream. The accumulation of lead in the downstream area is being enhanced if the industrial pollution control measure is neglected.

Regarding the lead contamination in the Chao Phraya Basin, the monitoring of 26 stations in the ten-year period was carried out. The 143 average values or 67 percent from 212 average values of lead occurrence were collected, and 47 average values or 22 percent were out of the standard. The lead contamination was in 1986 found at every station .And the finding indicated that the industries posting the main factor for lead presentation in the river.

The zoning of the lead polluted areas; for protection and conservation of environment, in the studied area can be classified into 3 zones.

Zone 1 - from Changwat Nakhon Sawan to Changwat Chainat, presented the lesser degree of contamination or the close to the natural resource.

Zone 2 - ranging Changwat Singburi, Changwat Ang-Thong, Changwat Pranakhon Sriayudhya and Changwat Pathum Thani is graded not severe or the "warning zone".

Zone 3 - in Changwat Nondhaburi, Bangkok and Changwat Samut Prakan, has shown the severe stage or the "risky zone".

For the application on public relation activities: zone 1 which is of low lead contamination the activities are emphasized on the conservation or natural resources and environment. Zone 2, the lead problem in recognized and tends to increase, the public relation activities should cover the industrial businesses and public. Zone 3, which was of the highest lead contamination, needs urgent implementation to encourage the industrial businesses and public to share their responsibility on the environment and on upgrading the water quality of the Chao Phraya River.