Monitoring of DDT in Agricultural Soils under Organic Farming in Poland and the Risk of Crop Contamination

Abstract

The analysis of 142 agricultural soil samples collected in organic farms across Poland with the intent to evaluate the level of DDT contamination resulted in more than 80% of the soils containing DDT. The ΣDDT (sum of all metabolites and isomers) concentration ranged between 0.005 and 0.383 mg/kg ΣDDT, with an average value of 0.064 mg/kg ΣDDT. However, the majority of plant samples collected from the crops growing on the sampled soils did not contain detectable DDT residues. The high DDT pollution levels detected in samples from four voivodeships (regions) among those monitored have been hypothesised to be linked to horticultural productions occurring to the sampled fields and typical of those regions, particularly in big-sized farms, during the period of DDT application, as well as the number of pesticides landfills present in these voivodeships. The elaboration of the o,p′-DDT/p,p′-DDT and DDT/(DDE + DDD) ratios to appraise the source or the period of contamination suggested that the contamination originated from past use of DDT rather than from impurities of more recent applications of other formulated substances. Such outcome thus suggests that the risk of contamination of organic products is likely derived from general environmental pollution levels rather than from the use of unauthorised substances in organic farming productions. Data from a trial with artificial contamination of soils indicated that using the DDT/(DDE + DDD) ratio in the presence of a low level of contamination could be less reliable than in highly contaminated soils.

Validation of a Method Scope Extension for the Analysis of POPs in Soil and Verification in Organic and Conventional Farms of the Canary Islands

“…As shown in Table 5 and Figure 5 (summations), we found significant differences in the concentrations of p,p’-DDE, p,p-DDD, and dieldrin, although in the opposite directions to those theorized by other authors [ 72 , 73 ]. Our results indicated that the concentration of organochlorines in farms devoted to mixed vegetable cultivation was much higher than that in vineyards, which would present levels very much in line with those reported recently in studies around the world [ 65 , 66 , 67 , 68 , 69 ]. This further highlights the need for robust and reliable analytical tools to routinely monitor levels of persistent and semi-persistent organic pollutants because, as we have seen, levels can vary greatly from place to place.…”

“…This further highlights the need for robust and reliable analytical tools to routinely monitor levels of persistent and semi-persistent organic pollutants because, as we have seen, levels can vary greatly from place to place. much in line with those reported recently in studies around the world [65][66][67][68][69]. This further highlights the need for robust and reliable analytical tools to routinely monitor levels of persistent and semi-persistent organic pollutants because, as we have seen, levels can vary greatly from place to place.…”

“…However, the levels of two contaminants (p,p'-DDE and p,p'-DDD) did attract our attention, not so much because of the frequency of detection, which was similar to that reported in other studies (>70% of the samples), but because of the high concentrations detected. In fact, p,p'-DDE levels in the samples of our series presented mean (364.6 ± 698.7 ng g −1 ) and median (58.7 ng g −1 ) values that are much higher than those reported in other recent studies in Turkey [65], India [66], Poland [67,68], or Iran [69]. In fact, the highest value in our series (2305.6 ng g −1 ), which paradoxically was found in a farm dedicated to organic vegetable farming, was about twice the median value reported for a region of Azerbaijan that has been reported to be historically contaminated by DDT (and its metabolites), because it was subjected to intensive aerial spraying campaigns [70].…”

A Genomic and Transcriptomic Study on the DDT-Resistant Trichoderma hamatum FBL 587: First Genetic Data into Mycoremediation Strategies for DDT-Polluted Sites

“…The plants were separated from soil and each plant fraction (root, aboveground and sometimes fruits) together with remaining soil were analysed for DDT residues. DDT and its metabolites were determined as described elsewhere [ 3 ].…”

“…Anthropogenic halogenic pollutants such as 1,1,1-Trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) and its metabolite products (e.g., 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDD), and 1,1-dichloro-2,2-bis (4-chlorophenyl) ethylene (DDE)) have accumulated in soils and pose significant health and environmental concerns [ 1 , 2 ]. In particular DDT-polluted agricultural sites are of great human health concern due to the environmental persistence of DDT and its metabolite products becoming long-term sources of exposure [ 3 ].…”