This project focuses on investigation of heavy metals in the environment in Changhua and Yunlin; the purposes of this project are as follows: 1)Conducting investigation of heavy metals in the environmental media such as air, water and soil, fishery and agriculture products, as well as investigation and analysis of odor sources in selected location. 2) Building a database of heavy metals in the environmental media, and analyzing possible sources of heavy metals that may impact the residents. 3) Assessing how different heavy metals in the environmental media affect the residents’ health, respectively.
To achieve the goal of the project, the key work is to conduct investigation of environmental heavy metal concentrations and odor pollution sources, including air, flue, tap water, groundwater, seawater, soil, agriculture and fishery products, and a database of different environmental heavy metals in Changhua and Yunlin area can be built to analyze possible sources of heavy metals that may affect the residents.
The results are summarized as follows:
(1) Before the investigation, consultative council was hold, with scholars and residents from the Environmental Protection Agency (EPA) and Dacheng Township in Changhua, in order to organize the recommendations and consensus in this project. The local residents were invited to attend the sampling training, as well as to join the sampling work. Also, the purpose of the environmental heavy metals investigation in Dacheng Township was introduced and briefed to the residents through different communicating medium.
(2) For odor survey, different investigation method were integrated. FTIR team from ITRI (Industrial Technology Research Institute) were invited to assist in the monitoring which can help to clarify the possible sources and species of the odor.
(3) Air quality monitoring methods of heavy metals includes automatic continuous and manual sampling during the northeast monsoon seasons and southwest monsoon season. Results of air quality survey shows that the major metal elements in the northeast monsoon season and the southwest monsoon season are similar. The major sources of dusty heavy metals are dust and riverbed dust, and harmful heavy metals are from various sources. In addition, the trend of concentration change of nickel (Ni) and vanadium (V) were similar. Pollution emissions may be derived from the heavy oil boilers or near-ocean vessels.
(4) There had been 10 flue detections done, and no considerable emission of carcinogenic heavy metals was tested. The concentration of particulate matter and heavy metals were much lower than the emission control standards.
(5) Composition of heavy metals in automotive fuels varies greatly among different suppliers. The samples’ concentrations were in line with the national regulation that lead (Pb) in the oil was less than 13 mg/L, and was similar to the oil in the EU.
(6) The indoor dust compositions of 10 households in Taixi Village of Dacheng Township were high in iron (Fe), aluminum (Al) and magnesium (Mg). Indoor dust were collected and sampled in 3 households in Taixi Village of Dacheng Township. The survey results are similar to the investigation made by the Changhua County Environmental Protection Bureau (EPB). According to the results, it is estimated that the resident in Taixi Village of Dacheng Township may take in up to 0.02 grams of dust per year.
(7) Canister sampling was initiated when the residents smell the odor. The results shows that the concentrations of most substances were below detection limits. Among the 14 samples, only acetone, dichlorodifluoromethane (Freon 12), methyl chloride, trichlorofluoromethane (Freon 11), dichloromethane, n-hexane, benzene and 1,2-dichloroethane were detected. In addition to canister sampling, sulfide monitoring was also operated in the north and south sides of the Zhuoshui River. The FTIR team from ITRI was invited to assist the monitoring, in order to clarify the potential sources and elements. The results did not show a significant source of industrial emissions. FTIR team will be in charge of tracing the source of odor.
(8) Concentration of magnesium and strontium are the highest in tap water, and it is found that the water filter can reduce the concentration of heavy metals. Most of the heavy metals in irrigation water meets the irrigation water quality standards, except for iron, manganese and arsenic, which at some location, exceeded water quality standards. Arsenic (As) is a heavy metal that is harmful to human health, it’s recommended that it should not be used as irrigation water. However, each sample of the plan is only monitored once, the continuous monitoring is still needed.
(9) The concentration of heavy metals in seawater meets the water quality standards of the sea area. Manganese (Mn), iron (Fe) and aluminum (Al) are slightly higher in the vicinity of the Changhua coastal area, it may be affected by coastal geology.
(10) As for soil, concentration of Arsenic in surface soil and subsoil shows nearly no difference. It may be caused by the local geographic attributes that the arsenic in the soil is naturally in higher concentration. However, the number of samples are too few to represent the whole, and further monitoring are suggested to be continued. Most of the concentration of heavy metals in groundwater meets groundwater pollution monitoring standards, except for iron and manganese.
(11) Fishery and agriculture products were in line with the maximum allowable amount of hygiene standards in food. The highest concentration is magnesium (Mg) and as followed by iron (Fe), aluminum (Al), manganese (Mn), zinc (Zn) and antimony (Sr) in the crops. Because of the different species of crops and the different growth periods, heavy metal accumulation was inconsistent in crops. For example, rice has stronger absorption capacity for chromium (Cr) than other crops. As the different feeding methods, it makes the major heavy metals proportion in fish and shellfish significantly different. Fishery are in a higher proportion of magnesium (Mg). Shellfish are in a higher proportion of magnesium (Mg), iron (Fe) and aluminum (Al). In addition, harmful heavy metals in fish and shellfish have higher concentrations of arsenic (As). Further analysis of inorganic arsenic and organic arsenic.
(12) The residents’ heavy metal exposure from different sources was estimated. Arsenic (As) and mercury (Hg) exposure are mainly from fish. Cadmium (Cd), chromium (Cr), and nickel (Ni) mainly derived from the crustaceous roots. Each heavy metal comes from a low proportion of breathing and drinking water. However, the number of samples for each medium surveyed was too less. The results are not representative. It can be able to more representative of the actual situation by continuous accumulation of survey data.
(13) The content of different heavy metals, which can be harmful to human bodies, was compared with which in different regions. Cadmium (Cd) and mercury (Hg) shows average concentrations in environmental media. Arsenic (As) is slightly higher condition in soil and water; it is possibly caused by geological factors. Nickel (Ni) is slightly higher condition in soil, irrigation water, seawater, rice, and shellfish. Concentrations of chromium (Cr) are also slightly higher in rice and shellfish. Lead (Pb) is slightly higher in fish and shellfish.
It is necessary to investigate the concentration of heavy metals in continuous for environmental media in this area. The trace and control of nickel (Ni) and chromium (Cr) from the wastewater source should be strengthened. For the residents, the results of the concentration in each survey are not extremely high. However, groundwater and unclean irrigation water sources should still be avoided. If the irrigation water source is found contaminated, it is suggested to contact the EPA immediately for the following investigation.
