Future studies focusing on parent compounds or pesticide-specific metabolites may be able to clearly elucidate associations between individual pesticide use and exposure. Additionally, DAPs in urine may reflect exposure to preformed DAPs in the environment or food rather than exposure to the parent compound and thus overestimate OP pesticide exposure. Finally, the modified food frequency questionnaire we used quantified maternal reported servings of fruits and vegetables consumed by the child each day, but was not calibrated to specific portion sizes. Thus, the use of reported servings in the analyses may have introduced uncontrolled variability. However, this type of non-differential exposure misclassification would tend to bias results toward the null hypothesis. In conclusion, we found that children living in an agricultural area are likely exposed to OP pesticides from multiple pathways, and total urinary DAP, in particular DMAP, metabolite levels increased with age. Diet and regional pesticide use are possible exposure sources. Given the health benefits of fresh fruit and vegetable consumption, we do not suggest that children limit intake of these foods but encourage washing of all produce before eating. While the OP pesticide metabolite levels in this population do not appear significantly higher than other populations, there are limited reference data available to make valid comparisons. OP pesticide exposures in children have been associated with poorer neurodevelopmental outcomes. Given the significance of these health studies, additional research is needed to better explain the trend of increasing OP urinary metabolites with age and the dietary, behavioral,square black flower bucket and other factors that determine exposure.Over the past decade, the annual U.S. trade balance with China has gone from a small surplus to a deficit of over $57 billion . The mounting trade deficit has resulted in renewed U. S. pressure to expand access to China’s markets. Recently, there have been intensive U.S.-China discussions over trade concessions and the related issue of China’s bid to join the World Trade Organization .
Agricultural trade is at the center of these negotiations as China’s high trade barriers in agriculture are believed to be partly responsible for the trade deficit.In a typical year, China has neither a large surplus nor a large deficit in its agricultural trade balance. For instance, in 1995, China ran a relatively small agricultural trade deficit of $1.47 billion and then in 1996 the balance shifted to become a small surplus, with agricultural exports exceeding imports by $673 million in that year.Even though its overall agricultural trade balance is small, China is a significant but erratic trader for certain agricultural commodities such as wheat, maize, oilseeds, edible oils, tobacco and cotton. China’s agricultural trade regime has not been liberalized to the same extent as its trade in manufactures . So there is great uncertainty as to what might happen if and when China liberalizes its agricultural trade. Some projections suggest that China will become a consistent net importer of food . Based on its large and growing population and fluctuating grain stockpiles, some fear that China could destabilize world markets after agricultural trade liberalization . Agricultural trade barriers will be a key issue with regard to China’s application to join the World Trade Organization . For instance, China’s non-tariff trade barriers in grains are very controversial. The barriers in grains are not transparent because China’s state trading in grains is conducted through its Cereal, Oil, and Foodstuffs Importing and Exporting Corporation . COFCO is one of the world’s largest STEs in agriculture, and over the past decade, COFCO has imported as much as 17 percent of world wheat traded, and exported as much as much as 10 percent of the world’s corn. The reemergence of China as a significant trading nation in merchandise trade has been described by West , Lardy , World Bank , Wall, Boke, and Xiangshou , and Naughton . Greater integration with the global economy began in the mid 1980s and is now recognized as a fundamental feature of China’s ongoing economic reform. Outside of agriculture, significant import tariff reductions have occurred in the past decade. As a measure of openness, China’s nominal value of exports grew by 13 percent annually from 1980 to 1996.
During the same time period, imports grew by 12 percent per year, on average. By 1997, China’s total trade accounted for about 3 percent of world trade, up from 0.8 percent in 1978. However, the degree to which China’s door is open to the world is debatable and China may be less open to foreign trade than initially appears . From 1986 to 1996, China’s growth in real merchandise trade exceeded growth in real GDP by 2.1 percent, which was not particularly high by international standards. For instance, during the same time period, growth in real trade less growth in real GDP was 6.9 percent in Thailand and 4.5 percent in the United States.China’s ratio of foreign trade to GDP rose from 13 percent in 1980 to about 35 percent in 1996, valued at the official exchange rate. However, this ratio may overstate the relative importance of foreign trade in China’s economy because it is based on the official exchange rate . If instead, the purchasing power parity exchange rate is used, trade as a percent of GDP has not changed all that much since the mid 1980s. Using the real exchange rate, China’s trade as a percent of GDP only grew slightly from 6.6 percent in 1986 to 7.1 percent in 1996 . In relative terms, India’s trade as percent of GDP grew faster than China’s over this time period, going from 3.9 percent to 4.5 percent. In comparison, Thailand’s trade as a percent of GDP grew from 14.7 percent to 31.3 percent from 1986 to 1996. Despite China’s move to lower average tariffs, China continues to restrict imports through a variety of barriers, including tariff-quotas, taxes, import quotas, import licenses, and state trading . In addition, China uses other non-tariff technical trade barriers such as sanitary and phytosanitary measures. These barriers are commonly applied to agricultural products. For instance, under the guise of phytosanitary measures, China prohibits imports of U.S. citrus .Lardy explains that the commodity composition of trade has changed along with domestic market reforms, and that trade patterns are more consistent with China’s comparative advantage, compared with the pre-reform and early reform time periods. China has shifted away from petroleum exports and has increased exports of labor-intensive manufactured goods, to the point where manufactured goods accounted for 85 percent of exports in 1996.
The share of primary commodities in total imports fell from a little over one-third in 1980 to about one-fifth by 1996. China’s agriculture has a comparative advantage in labor intensive crops, not grains . However, policy has tilted China’s agricultural production away from its comparative advantage which lies in non-grain activities. Naughton argues that China’s merchandise exports have shifted to reflect its abundant labor. Has this happened in agriculture? To what degree is agricultural production and trade becoming more specialized to capture its comparative advantage in labor intensive food products? From a conceptual basis, Anderson argued that China’s economic reform would have a significant impact on the pattern of agricultural trade. More recently, the same argument has been made from an empirical perspective by Wang and Wailes, Fang, and Tuan . Wailes, Fang,square black flower bucket wholesale and Tuan point out that the growth rates for China’s agricultural trade are much slower than for total trade and consequently the share of agricultural trade in total trade has declined quite dramatically. However, Wailes, Fang, and Tuan also argue that China’s agricultural trade has expanded rapidly and that the pattern of trade roughly adheres to the laws of comparative advantage. Alternatively, Anderson and Strutt find there has been little growth in China’s food import dependence. Wang has argued that China’s agricultural net trade structure is consistent with its resource endowment. He found that land-intensive bulk4 and processed intermediate commodities account for most of the imports, while labor-intensive horticultural and consumer ready products make up most of the agricultural exports. However, he based his analysis on 1995 and 1996 data, a periodduring which China had a temporary export blockage on grain exports. In late 1994, the central government placed a moratorium on grain exports in an effort to control higher domestic food prices. Rice and maize have traditionally been net exports but they shifted to a net import situation during the export blockade. Yiping Huang has argued that economic reforms in China have generated a significant impact on agricultural trade. He supported this observation with three points. His first point was that the growth of exports outpaced that of GDP during the reform period. Second, he noted that distortions to agricultural trade have been reduced significantly and agricultural trade experienced dramatic expansion. Third, he noted that trade was brought into conformity with the pattern of resource endowments.The trade reforms that have been implemented in China since 1979 are characterized by demonopolisation of foreign trade, the phasing out of trade subsidies, replacing of planned-quotas with a tariff- quota regime , progress toward currency convertibility, and provisions to attract foreign direct investment. The opening-up has been a means to promote economic growth and conform with general international trade rules so as to finally join the WTO. In general, some significant changes in the nature and extent of government trade interventions have occurred in China. Prior to the reform period, the allocation of imports and exports were strictly based on administrative planning and undertaken by only 12 foreign trade corporations.
The process of trade policy reform has involved the introduction of some competition in international trading and the gradual development of policy instruments for indirect controls. In 1984, the foreign trade system was decentralized considerably, when the provincial branches of national foreign trade corporations were allowed to become independent and each province was allowed to create its own FTCs. By 1986 there were about 1,200 FTCs, and by the early 1990’s they numbered more than 3,000. Although firms must obtain approval to engage in international trade, this permission has been granted very liberally and there are now approximately 200,000 firms eligible to engage in foreign trade . On the other hand, the foreign trade of so-called “strategic products” such as food grains, textile fibers, and chemical fertilizers, continue to be restricted to specialized national trading corporations with monopoly trading rights. China’s agricultural trade policy, particularly with regard to grain, is characterized by import/export licenses and quotas. But even in the case of agricultural trade, some progress has been made since the 1980s. The overall purpose of this paper is to measure this progress, relative to trade in manufactures and other primary commodities. Prior to the 1978 reforms, almost all of China’s foreign trade was subject to central planning through a small number of foreign trade corporations. For most sectors, the government has since replaced central planning over trade with import licenses and import and export tariffs. The opening of China’s economy involved policies to promote exports and attract foreign direct investment. However, agricultural trade is a major exception to this move towards decentralization of foreign trade. This is somewhat ironic because agriculture was largely responsible for the initial success of China’s overall economic reform.In China, rapid economic growth has been accompanied by dramatic changes in the structure of the economy. Agriculture’s share in the total economy has declined from about 40 percent of the GDP in 1970 to less than 20 percent in 1997. At the same time, agriculture’s share in total employment declined from 81 percent to 49 percent.5 The declining role of agriculture in the economy means the share of agricultural trade in China’s total trade has decreased significantly. In 1980, agriculture’s share of both exports and imports was around 30 percent, and this declined to about 10 percent in 1997. This is an indication of the improvement in resource allocation among sectors and the shifting of comparative advantage between agricultural and manufactured products. In nominal terms, the value of China’s agricultural exports grew at an average rate of 7.1 percent a year from 1980 to 1996.